diff --git a/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/clause/DistinctClause.java b/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/clause/DistinctClause.java
new file mode 100644
index 0000000..789c5bd
--- /dev/null
+++ b/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/clause/DistinctClause.java
@@ -0,0 +1,51 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.asterix.lang.aql.clause;
+
+import java.util.List;
+
+import org.apache.asterix.common.exceptions.AsterixException;
+import org.apache.asterix.lang.aql.visitor.base.IAQLVisitor;
+import org.apache.asterix.lang.common.base.Clause;
+import org.apache.asterix.lang.common.base.Expression;
+import org.apache.asterix.lang.common.visitor.base.ILangVisitor;
+
+public class DistinctClause implements Clause {
+
+    private List<Expression> distinctByExprs;
+
+    public DistinctClause(List<Expression> distinctByExpr) {
+        this.distinctByExprs = distinctByExpr;
+    }
+
+    public List<Expression> getDistinctByExpr() {
+        return distinctByExprs;
+    }
+
+    @Override
+    public ClauseType getClauseType() {
+        return ClauseType.DISTINCT_BY_CLAUSE;
+    }
+
+    @Override
+    public <R, T> R accept(ILangVisitor<R, T> visitor, T arg) throws AsterixException {
+        return ((IAQLVisitor<R, T>) visitor).visit(this, arg);
+    }
+
+}
diff --git a/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/clause/ForClause.java b/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/clause/ForClause.java
new file mode 100644
index 0000000..39e7bbb
--- /dev/null
+++ b/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/clause/ForClause.java
@@ -0,0 +1,87 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.asterix.lang.aql.clause;
+
+import org.apache.asterix.common.exceptions.AsterixException;
+import org.apache.asterix.lang.aql.visitor.base.IAQLVisitor;
+import org.apache.asterix.lang.common.base.Clause;
+import org.apache.asterix.lang.common.base.Expression;
+import org.apache.asterix.lang.common.expression.VariableExpr;
+import org.apache.asterix.lang.common.visitor.base.ILangVisitor;
+
+public class ForClause implements Clause {
+    private VariableExpr varExpr = null;
+    private VariableExpr posExpr = null;
+    private Expression inExpr = null;
+
+    public ForClause() {
+        super();
+    }
+
+    public ForClause(VariableExpr varExpr, Expression inExpr) {
+        super();
+        this.varExpr = varExpr;
+        this.inExpr = inExpr;
+    }
+
+    public ForClause(VariableExpr varExpr, Expression inExpr, VariableExpr posExpr) {
+        super();
+        this.varExpr = varExpr;
+        this.inExpr = inExpr;
+        this.posExpr = posExpr;
+    }
+
+    public VariableExpr getVarExpr() {
+        return varExpr;
+    }
+
+    public void setVarExpr(VariableExpr varExpr) {
+        this.varExpr = varExpr;
+    }
+
+    public Expression getInExpr() {
+        return inExpr;
+    }
+
+    public void setInExpr(Expression inExpr) {
+        this.inExpr = inExpr;
+    }
+
+    @Override
+    public ClauseType getClauseType() {
+        return ClauseType.FOR_CLAUSE;
+    }
+
+    @Override
+    public <R, T> R accept(ILangVisitor<R, T> visitor, T arg) throws AsterixException {
+        return ((IAQLVisitor<R, T>) visitor).visit(this, arg);
+    }
+
+    public void setPosExpr(VariableExpr posExpr) {
+        this.posExpr = posExpr;
+    }
+
+    public VariableExpr getPosVarExpr() {
+        return posExpr;
+    }
+
+    public boolean hasPosVar() {
+        return posExpr != null;
+    }
+}
diff --git a/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/clause/JoinClause.java b/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/clause/JoinClause.java
new file mode 100644
index 0000000..558bd52
--- /dev/null
+++ b/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/clause/JoinClause.java
@@ -0,0 +1,85 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.asterix.lang.aql.clause;
+
+import java.util.List;
+
+import org.apache.asterix.common.exceptions.AsterixException;
+import org.apache.asterix.lang.aql.visitor.base.IAQLPlusVisitor;
+import org.apache.asterix.lang.common.base.Clause;
+import org.apache.asterix.lang.common.base.Expression;
+import org.apache.asterix.lang.common.visitor.base.ILangVisitor;
+
+public class JoinClause implements Clause {
+
+    public static enum JoinKind {
+        INNER,
+        LEFT_OUTER
+    }
+
+    private Expression whereExpr;
+    private List<Clause> leftClauses, rightClauses;
+    private final JoinKind kind;
+
+    public JoinClause() {
+        kind = JoinKind.INNER;
+    }
+
+    public JoinClause(JoinKind kind) {
+        this.kind = kind;
+    }
+
+    @Override
+    public <R, T> R accept(ILangVisitor<R, T> visitor, T arg) throws AsterixException {
+        return ((IAQLPlusVisitor<R, T>) visitor).visitJoinClause(this, arg);
+    }
+
+    @Override
+    public ClauseType getClauseType() {
+        return null;
+    }
+
+    public List<Clause> getLeftClauses() {
+        return leftClauses;
+    }
+
+    public List<Clause> getRightClauses() {
+        return rightClauses;
+    }
+
+    public Expression getWhereExpr() {
+        return whereExpr;
+    }
+
+    public void setLeftClauses(List<Clause> leftClauses) {
+        this.leftClauses = leftClauses;
+    }
+
+    public void setRightClauses(List<Clause> righClauses) {
+        this.rightClauses = righClauses;
+    }
+
+    public void setWhereExpr(Expression whereExpr) {
+        this.whereExpr = whereExpr;
+    }
+
+    public JoinKind getKind() {
+        return kind;
+    }
+}
diff --git a/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/clause/MetaVariableClause.java b/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/clause/MetaVariableClause.java
new file mode 100644
index 0000000..a33699e
--- /dev/null
+++ b/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/clause/MetaVariableClause.java
@@ -0,0 +1,47 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.asterix.lang.aql.clause;
+
+import org.apache.asterix.common.exceptions.AsterixException;
+import org.apache.asterix.lang.aql.visitor.base.IAQLPlusVisitor;
+import org.apache.asterix.lang.common.base.Clause;
+import org.apache.asterix.lang.common.struct.VarIdentifier;
+import org.apache.asterix.lang.common.visitor.base.ILangVisitor;
+
+public class MetaVariableClause implements Clause {
+    private VarIdentifier var;
+
+    @Override
+    public <R, T> R accept(ILangVisitor<R, T> visitor, T arg) throws AsterixException {
+        return ((IAQLPlusVisitor<R, T>) visitor).visitMetaVariableClause(this, arg);
+    }
+
+    @Override
+    public ClauseType getClauseType() {
+        return null;
+    }
+
+    public VarIdentifier getVar() {
+        return var;
+    }
+
+    public void setVar(VarIdentifier var) {
+        this.var = var;
+    }
+}
diff --git a/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/expression/FLWOGRExpression.java b/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/expression/FLWOGRExpression.java
new file mode 100644
index 0000000..0761396
--- /dev/null
+++ b/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/expression/FLWOGRExpression.java
@@ -0,0 +1,78 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.asterix.lang.aql.expression;
+
+import java.util.List;
+
+import org.apache.asterix.common.exceptions.AsterixException;
+import org.apache.asterix.lang.aql.visitor.base.IAQLVisitor;
+import org.apache.asterix.lang.common.base.Clause;
+import org.apache.asterix.lang.common.base.Clause.ClauseType;
+import org.apache.asterix.lang.common.base.Expression;
+import org.apache.asterix.lang.common.visitor.base.ILangVisitor;
+
+public class FLWOGRExpression implements Expression {
+    private List<Clause> clauseList;
+    private Expression returnExpr;
+
+    public FLWOGRExpression() {
+        super();
+    }
+
+    public FLWOGRExpression(List<Clause> clauseList, Expression returnExpr) {
+        super();
+        this.clauseList = clauseList;
+        this.returnExpr = returnExpr;
+    }
+
+    public List<Clause> getClauseList() {
+        return clauseList;
+    }
+
+    public void setClauseList(List<Clause> clauseList) {
+        this.clauseList = clauseList;
+    }
+
+    public Expression getReturnExpr() {
+        return returnExpr;
+    }
+
+    public void setReturnExpr(Expression returnExpr) {
+        this.returnExpr = returnExpr;
+    }
+
+    @Override
+    public Kind getKind() {
+        return Kind.FLWOGR_EXPRESSION;
+    }
+
+    public boolean noForClause() {
+        for (Clause c : clauseList) {
+            if (c.getClauseType() == ClauseType.FOR_CLAUSE) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    @Override
+    public <R, T> R accept(ILangVisitor<R, T> visitor, T arg) throws AsterixException {
+        return ((IAQLVisitor<R, T>) visitor).visit(this, arg);
+    }
+}
diff --git a/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/expression/MetaVariableExpr.java b/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/expression/MetaVariableExpr.java
new file mode 100644
index 0000000..99c7902
--- /dev/null
+++ b/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/expression/MetaVariableExpr.java
@@ -0,0 +1,42 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.asterix.lang.aql.expression;
+
+import org.apache.asterix.common.exceptions.AsterixException;
+import org.apache.asterix.lang.aql.visitor.base.IAQLPlusVisitor;
+import org.apache.asterix.lang.common.expression.VariableExpr;
+import org.apache.asterix.lang.common.visitor.base.ILangVisitor;
+
+public class MetaVariableExpr extends VariableExpr {
+
+    @Override
+    public <R, T> R accept(ILangVisitor<R, T> visitor, T arg) throws AsterixException {
+        return ((IAQLPlusVisitor<R, T>) visitor).visitMetaVariableExpr(this, arg);
+    }
+
+    @Override
+    public boolean getIsNewVar() {
+        return false;
+    }
+
+    @Override
+    public Kind getKind() {
+        return Kind.METAVARIABLE_EXPRESSION;
+    }
+}
diff --git a/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/expression/UnionExpr.java b/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/expression/UnionExpr.java
new file mode 100644
index 0000000..2c8756b
--- /dev/null
+++ b/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/expression/UnionExpr.java
@@ -0,0 +1,62 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.asterix.lang.aql.expression;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.apache.asterix.common.exceptions.AsterixException;
+import org.apache.asterix.lang.aql.visitor.base.IAQLVisitor;
+import org.apache.asterix.lang.common.base.Expression;
+import org.apache.asterix.lang.common.visitor.base.ILangVisitor;
+
+public class UnionExpr implements Expression {
+
+    private List<Expression> exprs;
+
+    public UnionExpr() {
+        exprs = new ArrayList<Expression>();
+    }
+
+    public UnionExpr(List<Expression> exprs) {
+        this.exprs = exprs;
+    }
+
+    @Override
+    public Kind getKind() {
+        return Kind.UNION_EXPRESSION;
+    }
+
+    public List<Expression> getExprs() {
+        return exprs;
+    }
+
+    public void setExprs(List<Expression> exprs) {
+        this.exprs = exprs;
+    }
+
+    public void addExpr(Expression exp) {
+        exprs.add(exp);
+    }
+
+    @Override
+    public <R, T> R accept(ILangVisitor<R, T> visitor, T arg) throws AsterixException {
+        return ((IAQLVisitor<R, T>) visitor).visit(this, arg);
+    }
+}
diff --git a/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/rewrites/AqlRewriter.java b/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/rewrites/AqlRewriter.java
new file mode 100644
index 0000000..dc99549
--- /dev/null
+++ b/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/rewrites/AqlRewriter.java
@@ -0,0 +1,234 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.asterix.lang.aql.rewrites;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Set;
+
+import org.apache.asterix.common.exceptions.AsterixException;
+import org.apache.asterix.common.functions.FunctionSignature;
+import org.apache.asterix.lang.aql.clause.DistinctClause;
+import org.apache.asterix.lang.aql.clause.ForClause;
+import org.apache.asterix.lang.aql.expression.FLWOGRExpression;
+import org.apache.asterix.lang.aql.expression.UnionExpr;
+import org.apache.asterix.lang.aql.util.FunctionUtils;
+import org.apache.asterix.lang.aql.visitor.AQLInlineUdfsVisitor;
+import org.apache.asterix.lang.aql.visitor.base.IAQLVisitor;
+import org.apache.asterix.lang.common.base.Clause;
+import org.apache.asterix.lang.common.base.Expression;
+import org.apache.asterix.lang.common.base.Expression.Kind;
+import org.apache.asterix.lang.common.clause.GroupbyClause;
+import org.apache.asterix.lang.common.clause.LetClause;
+import org.apache.asterix.lang.common.expression.GbyVariableExpressionPair;
+import org.apache.asterix.lang.common.expression.VariableExpr;
+import org.apache.asterix.lang.common.rewrites.LangRewritingContext;
+import org.apache.asterix.lang.common.statement.FunctionDecl;
+import org.apache.asterix.lang.common.statement.Query;
+import org.apache.asterix.lang.common.struct.VarIdentifier;
+import org.apache.asterix.lang.common.visitor.GatherFunctionCallsVisitor;
+import org.apache.asterix.metadata.MetadataManager;
+import org.apache.asterix.metadata.MetadataTransactionContext;
+import org.apache.asterix.metadata.declared.AqlMetadataProvider;
+import org.apache.asterix.metadata.entities.Function;
+import org.apache.asterix.om.functions.AsterixBuiltinFunctions;
+
+public final class AqlRewriter {
+
+    private final Query topExpr;
+    private final List<FunctionDecl> declaredFunctions;
+    private final LangRewritingContext context;
+    private final MetadataTransactionContext mdTxnCtx;
+    private final AqlMetadataProvider metadataProvider;
+
+    public AqlRewriter(List<FunctionDecl> declaredFunctions, Query topExpr, AqlMetadataProvider metadataProvider) {
+        this.topExpr = topExpr;
+        context = new LangRewritingContext(topExpr.getVarCounter());
+        this.declaredFunctions = declaredFunctions;
+        this.mdTxnCtx = metadataProvider.getMetadataTxnContext();
+        this.metadataProvider = metadataProvider;
+    }
+
+    public Query getExpr() {
+        return topExpr;
+    }
+
+    public int getVarCounter() {
+        return context.getVarCounter();
+    }
+
+    public void rewrite() throws AsterixException {
+        wrapInLets();
+        inlineDeclaredUdfs();
+    }
+
+    private void wrapInLets() {
+        // If the top expression of the main statement is not a FLWOR, it wraps
+        // it into a let clause.
+        if (topExpr == null) {
+            return;
+        }
+        Expression body = topExpr.getBody();
+        if (body.getKind() != Kind.FLWOGR_EXPRESSION) {
+            VarIdentifier var = context.newVariable();
+            VariableExpr v = new VariableExpr(var);
+            LetClause c1 = new LetClause(v, body);
+            ArrayList<Clause> clauseList = new ArrayList<Clause>(1);
+            clauseList.add(c1);
+            FLWOGRExpression newBody = new FLWOGRExpression(clauseList, new VariableExpr(var));
+            topExpr.setBody(newBody);
+        }
+    }
+
+    private void inlineDeclaredUdfs() throws AsterixException {
+        if (topExpr == null) {
+            return;
+        }
+        List<FunctionSignature> funIds = new ArrayList<FunctionSignature>();
+        for (FunctionDecl fdecl : declaredFunctions) {
+            funIds.add(fdecl.getSignature());
+        }
+
+        List<FunctionDecl> otherFDecls = new ArrayList<FunctionDecl>();
+        buildOtherUdfs(topExpr.getBody(), otherFDecls, funIds);
+        declaredFunctions.addAll(otherFDecls);
+        if (!declaredFunctions.isEmpty()) {
+            AQLInlineUdfsVisitor visitor = new AQLInlineUdfsVisitor(context);
+            while (topExpr.accept(visitor, declaredFunctions)) {
+                // loop until no more changes
+            }
+        }
+        declaredFunctions.removeAll(otherFDecls);
+    }
+
+    private void buildOtherUdfs(Expression expression, List<FunctionDecl> functionDecls,
+            List<FunctionSignature> declaredFunctions) throws AsterixException {
+        if (expression == null) {
+            return;
+        }
+        String value = metadataProvider.getConfig().get(FunctionUtils.IMPORT_PRIVATE_FUNCTIONS);
+        boolean includePrivateFunctions = (value != null) ? Boolean.valueOf(value.toLowerCase()) : false;
+        Set<FunctionSignature> functionCalls = getFunctionCalls(expression);
+        for (FunctionSignature signature : functionCalls) {
+
+            if (declaredFunctions != null && declaredFunctions.contains(signature)) {
+                continue;
+            }
+
+            Function function = lookupUserDefinedFunctionDecl(signature);
+            if (function == null) {
+                if (AsterixBuiltinFunctions.isBuiltinCompilerFunction(signature, includePrivateFunctions)) {
+                    continue;
+                }
+                StringBuilder messageBuilder = new StringBuilder();
+                if (functionDecls.size() > 0) {
+                    messageBuilder.append(" function " + functionDecls.get(functionDecls.size() - 1).getSignature()
+                            + " depends upon function " + signature + " which is undefined");
+                } else {
+                    messageBuilder.append(" function " + signature + " is undefined ");
+                }
+                throw new AsterixException(messageBuilder.toString());
+            }
+
+            if (function.getLanguage().equalsIgnoreCase(Function.LANGUAGE_AQL)) {
+                FunctionDecl functionDecl = FunctionUtils.getFunctionDecl(function);
+                if (functionDecl != null) {
+                    if (functionDecls.contains(functionDecl)) {
+                        throw new AsterixException("ERROR:Recursive invocation "
+                                + functionDecls.get(functionDecls.size() - 1).getSignature() + " <==> "
+                                + functionDecl.getSignature());
+                    }
+                    functionDecls.add(functionDecl);
+                    buildOtherUdfs(functionDecl.getFuncBody(), functionDecls, declaredFunctions);
+                }
+            }
+        }
+
+    }
+
+    private Function lookupUserDefinedFunctionDecl(FunctionSignature signature) throws AsterixException {
+        if (signature.getNamespace() == null) {
+            return null;
+        }
+        return MetadataManager.INSTANCE.getFunction(mdTxnCtx, signature);
+    }
+
+    private Set<FunctionSignature> getFunctionCalls(Expression expression) throws AsterixException {
+        GatherFunctionCalls gfc = new GatherFunctionCalls();
+        expression.accept(gfc, null);
+        return gfc.getCalls();
+    }
+
+    private static class GatherFunctionCalls extends GatherFunctionCallsVisitor implements IAQLVisitor<Void, Void> {
+
+        public GatherFunctionCalls() {
+        }
+
+        @Override
+        public Void visit(DistinctClause dc, Void arg) throws AsterixException {
+            for (Expression e : dc.getDistinctByExpr()) {
+                e.accept(this, arg);
+            }
+            return null;
+        }
+
+        @Override
+        public Void visit(FLWOGRExpression flwor, Void arg) throws AsterixException {
+            for (Clause c : flwor.getClauseList()) {
+                c.accept(this, arg);
+            }
+            flwor.getReturnExpr().accept(this, arg);
+            return null;
+        }
+
+        @Override
+        public Void visit(ForClause fc, Void arg) throws AsterixException {
+            fc.getInExpr().accept(this, arg);
+            if (fc.getPosVarExpr() != null) {
+                fc.getPosVarExpr().accept(this, arg);
+            }
+            return null;
+        }
+
+        @Override
+        public Void visit(GroupbyClause gc, Void arg) throws AsterixException {
+            for (GbyVariableExpressionPair p : gc.getGbyPairList()) {
+                p.getExpr().accept(this, arg);
+            }
+            for (GbyVariableExpressionPair p : gc.getDecorPairList()) {
+                p.getExpr().accept(this, arg);
+            }
+            return null;
+        }
+
+        @Override
+        public Void visit(LetClause lc, Void arg) throws AsterixException {
+            lc.getBindingExpr().accept(this, arg);
+            return null;
+        }
+
+        @Override
+        public Void visit(UnionExpr u, Void arg) throws AsterixException {
+            for (Expression e : u.getExprs()) {
+                e.accept(this, arg);
+            }
+            return null;
+        }
+    }
+}
diff --git a/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/statement/SubscribeFeedStatement.java b/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/statement/SubscribeFeedStatement.java
new file mode 100644
index 0000000..a86c409
--- /dev/null
+++ b/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/statement/SubscribeFeedStatement.java
@@ -0,0 +1,209 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.asterix.lang.aql.statement;
+
+import java.io.StringReader;
+import java.util.List;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+import org.apache.asterix.common.exceptions.AsterixException;
+import org.apache.asterix.common.feeds.FeedActivity;
+import org.apache.asterix.common.feeds.FeedConnectionRequest;
+import org.apache.asterix.common.feeds.FeedId;
+import org.apache.asterix.common.feeds.FeedPolicyAccessor;
+import org.apache.asterix.common.functions.FunctionSignature;
+import org.apache.asterix.lang.aql.parser.AQLParser;
+import org.apache.asterix.lang.aql.parser.ParseException;
+import org.apache.asterix.lang.aql.util.FunctionUtils;
+import org.apache.asterix.lang.common.base.Statement;
+import org.apache.asterix.lang.common.statement.InsertStatement;
+import org.apache.asterix.lang.common.statement.Query;
+import org.apache.asterix.lang.common.visitor.base.ILangVisitor;
+import org.apache.asterix.metadata.MetadataException;
+import org.apache.asterix.metadata.MetadataManager;
+import org.apache.asterix.metadata.MetadataTransactionContext;
+import org.apache.asterix.metadata.entities.DatasourceAdapter.AdapterType;
+import org.apache.asterix.metadata.entities.Feed;
+import org.apache.asterix.metadata.entities.Function;
+import org.apache.asterix.metadata.entities.PrimaryFeed;
+import org.apache.asterix.metadata.entities.SecondaryFeed;
+import org.apache.asterix.metadata.feeds.FeedUtil;
+import org.apache.asterix.metadata.feeds.IFeedAdapterFactory;
+import org.apache.asterix.om.types.ARecordType;
+import org.apache.hyracks.algebricks.common.exceptions.AlgebricksException;
+import org.apache.hyracks.algebricks.common.utils.Triple;
+
+/**
+ * Represents the AQL statement for subscribing to a feed.
+ * This AQL statement is private and may not be used by the end-user.
+ */
+public class SubscribeFeedStatement implements Statement {
+
+    private static final Logger LOGGER = Logger.getLogger(SubscribeFeedStatement.class.getName());
+    private final FeedConnectionRequest connectionRequest;
+    private Query query;
+    private int varCounter;
+    private final String[] locations;
+
+    public static final String WAIT_FOR_COMPLETION = "wait-for-completion-feed";
+
+    public SubscribeFeedStatement(String[] locations, FeedConnectionRequest subscriptionRequest) {
+        this.connectionRequest = subscriptionRequest;
+        this.varCounter = 0;
+        this.locations = locations;
+    }
+
+    public void initialize(MetadataTransactionContext mdTxnCtx) throws MetadataException {
+        this.query = new Query();
+        FeedId sourceFeedId = connectionRequest.getFeedJointKey().getFeedId();
+        Feed subscriberFeed = MetadataManager.INSTANCE.getFeed(mdTxnCtx,
+                connectionRequest.getReceivingFeedId().getDataverse(),
+                connectionRequest.getReceivingFeedId().getFeedName());
+        if (subscriberFeed == null) {
+            throw new IllegalStateException(" Subscriber feed " + subscriberFeed + " not found.");
+        }
+
+        String feedOutputType = getOutputType(mdTxnCtx);
+        FunctionSignature appliedFunction = subscriberFeed.getAppliedFunction();
+        Function function = null;
+        if (appliedFunction != null) {
+            function = MetadataManager.INSTANCE.getFunction(mdTxnCtx, appliedFunction);
+            if (function == null) {
+                throw new MetadataException(" Unknown function " + function);
+            } else if (function.getParams().size() > 1) {
+                throw new MetadataException(
+                        " Incompatible function: " + appliedFunction + " Number if arguments must be 1");
+            }
+        }
+
+        StringBuilder builder = new StringBuilder();
+        builder.append("use dataverse " + sourceFeedId.getDataverse() + ";\n");
+        builder.append("set" + " " + FunctionUtils.IMPORT_PRIVATE_FUNCTIONS + " " + "'" + Boolean.TRUE + "'" + ";\n");
+        builder.append("set" + " " + FeedActivity.FeedActivityDetails.FEED_POLICY_NAME + " " + "'"
+                + connectionRequest.getPolicy() + "'" + ";\n");
+
+        builder.append("insert into dataset " + connectionRequest.getTargetDataset() + " ");
+        builder.append(" (" + " for $x in feed-collect ('" + sourceFeedId.getDataverse() + "'" + "," + "'"
+                + sourceFeedId.getFeedName() + "'" + "," + "'" + connectionRequest.getReceivingFeedId().getFeedName()
+                + "'" + "," + "'" + connectionRequest.getSubscriptionLocation().name() + "'" + "," + "'"
+                + connectionRequest.getTargetDataset() + "'" + "," + "'" + feedOutputType + "'" + ")");
+
+        List<String> functionsToApply = connectionRequest.getFunctionsToApply();
+        if (functionsToApply != null && functionsToApply.isEmpty()) {
+            builder.append(" return $x");
+        } else {
+            String rValueName = "x";
+            String lValueName = "y";
+            int variableIndex = 0;
+            for (String functionName : functionsToApply) {
+                function = MetadataManager.INSTANCE.getFunction(mdTxnCtx, appliedFunction);
+                variableIndex++;
+                switch (function.getLanguage().toUpperCase()) {
+                    case Function.LANGUAGE_AQL:
+                        builder.append(
+                                " let " + "$" + lValueName + variableIndex + ":=(" + function.getFunctionBody() + ")");
+                        builder.append("\n");
+                        break;
+                    case Function.LANGUAGE_JAVA:
+                        builder.append(" let " + "$" + lValueName + variableIndex + ":=" + functionName + "(" + "$"
+                                + rValueName + ")");
+                        rValueName = lValueName + variableIndex;
+                        break;
+                }
+                builder.append("\n");
+            }
+            builder.append("return $" + lValueName + variableIndex);
+        }
+        builder.append(")");
+        builder.append(";");
+        if (LOGGER.isLoggable(Level.INFO)) {
+            LOGGER.info("Connect feed statement translated to\n" + builder.toString());
+        }
+        AQLParser parser = new AQLParser(new StringReader(builder.toString()));
+
+        List<Statement> statements;
+        try {
+            statements = parser.Statement();
+            query = ((InsertStatement) statements.get(3)).getQuery();
+        } catch (ParseException pe) {
+            throw new MetadataException(pe);
+        }
+
+    }
+
+    public Query getQuery() {
+        return query;
+    }
+
+    public int getVarCounter() {
+        return varCounter;
+    }
+
+    @Override
+    public Kind getKind() {
+        return Kind.SUBSCRIBE_FEED;
+    }
+
+    public String getPolicy() {
+        return connectionRequest.getPolicy();
+    }
+
+    public FeedConnectionRequest getSubscriptionRequest() {
+        return connectionRequest;
+    }
+
+    @Override
+    public <R, T> R accept(ILangVisitor<R, T> visitor, T arg) throws AsterixException {
+        return null;
+    }
+
+    public String getDataverseName() {
+        return connectionRequest.getReceivingFeedId().getDataverse();
+    }
+
+    private String getOutputType(MetadataTransactionContext mdTxnCtx) throws MetadataException {
+        String outputType = null;
+        FeedId feedId = connectionRequest.getReceivingFeedId();
+        Feed feed = MetadataManager.INSTANCE.getFeed(mdTxnCtx, feedId.getDataverse(), feedId.getFeedName());
+        FeedPolicyAccessor policyAccessor = new FeedPolicyAccessor(connectionRequest.getPolicyParameters());
+        try {
+            switch (feed.getFeedType()) {
+                case PRIMARY:
+                    Triple<IFeedAdapterFactory, ARecordType, AdapterType> factoryOutput = null;
+
+                    factoryOutput = FeedUtil.getPrimaryFeedFactoryAndOutput((PrimaryFeed) feed, policyAccessor,
+                            mdTxnCtx);
+                    outputType = factoryOutput.second.getTypeName();
+                    break;
+                case SECONDARY:
+                    outputType = FeedUtil.getSecondaryFeedOutput((SecondaryFeed) feed, policyAccessor, mdTxnCtx);
+                    break;
+            }
+            return outputType;
+
+        } catch (AlgebricksException ae) {
+            throw new MetadataException(ae);
+        }
+    }
+
+    public String[] getLocations() {
+        return locations;
+    }
+}
diff --git a/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/util/AQLFormatPrintUtil.java b/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/util/AQLFormatPrintUtil.java
new file mode 100644
index 0000000..c97e642
--- /dev/null
+++ b/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/util/AQLFormatPrintUtil.java
@@ -0,0 +1,66 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.asterix.lang.aql.util;
+
+import java.io.ByteArrayOutputStream;
+import java.io.PrintWriter;
+import java.util.List;
+
+import org.apache.asterix.common.exceptions.AsterixException;
+import org.apache.asterix.lang.aql.visitor.AQLFormatPrintVisitor;
+import org.apache.asterix.lang.aql.visitor.AQLToSQLPPPrintVisitor;
+import org.apache.asterix.lang.common.base.ILangExpression;
+import org.apache.asterix.lang.common.base.Statement;
+
+public class AQLFormatPrintUtil {
+
+    public static void print(ILangExpression expr, PrintWriter output) throws AsterixException {
+        AQLFormatPrintVisitor visitor = new AQLFormatPrintVisitor(output);
+        expr.accept(visitor, 0);
+    }
+
+    public static void print(List<Statement> exprs, PrintWriter output) throws AsterixException {
+        AQLFormatPrintVisitor visitor = new AQLFormatPrintVisitor(output);
+        for (Statement expr : exprs) {
+            expr.accept(visitor, 0);
+        }
+    }
+
+    public static String toString(List<Statement> exprs) throws AsterixException {
+        ByteArrayOutputStream bos = new ByteArrayOutputStream();
+        PrintWriter output = new PrintWriter(bos);
+        AQLFormatPrintVisitor visitor = new AQLFormatPrintVisitor(output);
+        for (Statement expr : exprs) {
+            expr.accept(visitor, 0);
+        }
+        output.close();
+        return new String(bos.toByteArray());
+    }
+
+    public static String toSQLPPString(List<Statement> exprs) throws AsterixException {
+        ByteArrayOutputStream bos = new ByteArrayOutputStream();
+        PrintWriter output = new PrintWriter(bos);
+        AQLToSQLPPPrintVisitor visitor = new AQLToSQLPPPrintVisitor(output);
+        for (Statement expr : exprs) {
+            expr.accept(visitor, 0);
+        }
+        output.close();
+        return new String(bos.toByteArray());
+    }
+}
diff --git a/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/util/AQLVariableSubstitutionUtil.java b/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/util/AQLVariableSubstitutionUtil.java
new file mode 100644
index 0000000..06e6fa7
--- /dev/null
+++ b/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/util/AQLVariableSubstitutionUtil.java
@@ -0,0 +1,55 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.asterix.lang.aql.util;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+
+import org.apache.asterix.common.exceptions.AsterixException;
+import org.apache.asterix.lang.aql.visitor.AQLCloneAndSubstituteVariablesVisitor;
+import org.apache.asterix.lang.common.base.Expression;
+import org.apache.asterix.lang.common.base.ILangExpression;
+import org.apache.asterix.lang.common.expression.VariableExpr;
+import org.apache.asterix.lang.common.rewrites.LangRewritingContext;
+import org.apache.asterix.lang.common.rewrites.VariableSubstitutionEnvironment;
+
+public class AQLVariableSubstitutionUtil {
+
+    public static List<ILangExpression> substituteVariable(List<ILangExpression> expressions,
+            Map<VariableExpr, Expression> varExprMap) throws AsterixException {
+        AQLCloneAndSubstituteVariablesVisitor visitor = new AQLCloneAndSubstituteVariablesVisitor(
+                new LangRewritingContext(0));
+        VariableSubstitutionEnvironment env = new VariableSubstitutionEnvironment(varExprMap);
+        List<ILangExpression> newExprs = new ArrayList<ILangExpression>();
+        for (ILangExpression expression : expressions) {
+            newExprs.add(expression.accept(visitor, env).first);
+        }
+        return newExprs;
+    }
+
+    public static ILangExpression substituteVariable(ILangExpression expression,
+            Map<VariableExpr, Expression> varExprMap) throws AsterixException {
+        AQLCloneAndSubstituteVariablesVisitor visitor = new AQLCloneAndSubstituteVariablesVisitor(
+                new LangRewritingContext(0));
+        VariableSubstitutionEnvironment env = new VariableSubstitutionEnvironment(varExprMap);
+        return expression.accept(visitor, env).first;
+    }
+
+}
diff --git a/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/util/FunctionUtils.java b/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/util/FunctionUtils.java
new file mode 100644
index 0000000..2f326ae
--- /dev/null
+++ b/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/util/FunctionUtils.java
@@ -0,0 +1,81 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.apache.asterix.lang.aql.util;
+
+import java.io.StringReader;
+import java.util.ArrayList;
+import java.util.List;
+
+import org.apache.asterix.common.exceptions.AsterixException;
+import org.apache.asterix.common.functions.FunctionSignature;
+import org.apache.asterix.lang.aql.parser.AQLParser;
+import org.apache.asterix.lang.common.base.Statement;
+import org.apache.asterix.lang.common.statement.FunctionDecl;
+import org.apache.asterix.lang.common.struct.VarIdentifier;
+import org.apache.asterix.metadata.entities.Function;
+import org.apache.asterix.om.functions.AsterixBuiltinFunctions;
+import org.apache.hyracks.algebricks.core.algebra.functions.FunctionIdentifier;
+import org.apache.hyracks.algebricks.core.algebra.functions.IFunctionInfo;
+
+public class FunctionUtils {
+
+    public static final String IMPORT_PRIVATE_FUNCTIONS = "import-private-functions";
+
+    public static FunctionDecl getFunctionDecl(Function function) throws AsterixException {
+        String functionBody = function.getFunctionBody();
+        List<String> params = function.getParams();
+        List<VarIdentifier> varIdentifiers = new ArrayList<VarIdentifier>();
+
+        StringBuilder builder = new StringBuilder();
+        builder.append(" use dataverse " + function.getDataverseName() + ";");
+        builder.append(" declare function " + function.getName().split("@")[0]);
+        builder.append("(");
+        for (String param : params) {
+            VarIdentifier varId = new VarIdentifier(param);
+            varIdentifiers.add(varId);
+            builder.append(param);
+            builder.append(",");
+        }
+        if (params.size() > 0) {
+            builder.delete(builder.length() - 1, builder.length());
+        }
+        builder.append(")");
+        builder.append("{");
+        builder.append("\n");
+        builder.append(functionBody);
+        builder.append("\n");
+        builder.append("}");
+
+        AQLParser parser = new AQLParser(new StringReader(new String(builder)));
+
+        List<Statement> statements = parser.parse();
+        FunctionDecl decl = (FunctionDecl) statements.get(1);
+        return decl;
+    }
+
+    public static IFunctionInfo getFunctionInfo(FunctionIdentifier fi) {
+        return AsterixBuiltinFunctions.getAsterixFunctionInfo(fi);
+    }
+
+    public static IFunctionInfo getFunctionInfo(FunctionSignature fs) {
+        return getFunctionInfo(new FunctionIdentifier(fs.getNamespace(), fs.getName(), fs.getArity()));
+    }
+
+}
diff --git a/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/util/RangeMapBuilder.java b/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/util/RangeMapBuilder.java
new file mode 100644
index 0000000..a15fb45
--- /dev/null
+++ b/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/util/RangeMapBuilder.java
@@ -0,0 +1,174 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.asterix.lang.aql.util;
+
+import java.io.DataOutput;
+import java.util.List;
+
+import org.apache.asterix.common.exceptions.AsterixException;
+import org.apache.asterix.formats.nontagged.AqlBinaryComparatorFactoryProvider;
+import org.apache.asterix.formats.nontagged.AqlSerializerDeserializerProvider;
+import org.apache.asterix.lang.aql.parser.AQLParser;
+import org.apache.asterix.lang.common.base.Expression;
+import org.apache.asterix.lang.common.base.Expression.Kind;
+import org.apache.asterix.lang.common.base.Literal;
+import org.apache.asterix.lang.common.base.Statement;
+import org.apache.asterix.lang.common.expression.ListConstructor;
+import org.apache.asterix.lang.common.expression.LiteralExpr;
+import org.apache.asterix.lang.common.literal.DoubleLiteral;
+import org.apache.asterix.lang.common.literal.FloatLiteral;
+import org.apache.asterix.lang.common.literal.IntegerLiteral;
+import org.apache.asterix.lang.common.literal.LongIntegerLiteral;
+import org.apache.asterix.lang.common.literal.StringLiteral;
+import org.apache.asterix.lang.common.statement.Query;
+import org.apache.asterix.om.base.AMutableDouble;
+import org.apache.asterix.om.base.AMutableFloat;
+import org.apache.asterix.om.base.AMutableInt32;
+import org.apache.asterix.om.base.AMutableInt64;
+import org.apache.asterix.om.base.AMutableString;
+import org.apache.asterix.om.types.ATypeTag;
+import org.apache.asterix.om.types.BuiltinType;
+import org.apache.hyracks.algebricks.common.exceptions.NotImplementedException;
+import org.apache.hyracks.api.dataflow.value.IBinaryComparator;
+import org.apache.hyracks.api.dataflow.value.IBinaryComparatorFactory;
+import org.apache.hyracks.api.dataflow.value.ISerializerDeserializer;
+import org.apache.hyracks.api.exceptions.HyracksDataException;
+import org.apache.hyracks.data.std.util.ArrayBackedValueStorage;
+import org.apache.hyracks.dataflow.common.data.partition.range.IRangeMap;
+import org.apache.hyracks.dataflow.common.data.partition.range.RangeMap;
+
+public abstract class RangeMapBuilder {
+
+    public static IRangeMap parseHint(Object hint) throws AsterixException {
+        ArrayBackedValueStorage abvs = new ArrayBackedValueStorage();
+        DataOutput out = abvs.getDataOutput();;
+        abvs.reset();
+
+        AQLParser parser = new AQLParser((String) hint);
+        List<Statement> hintStatements = parser.parse();
+        if (hintStatements.size() != 1) {
+            throw new AsterixException("Only one range statement is allowed for the range hint.");
+        }
+
+        // Translate the query into a Range Map
+        if (hintStatements.get(0).getKind() != Statement.Kind.QUERY) {
+            throw new AsterixException("Not a proper query for the range hint.");
+        }
+        Query q = (Query) hintStatements.get(0);
+
+        if (q.getBody().getKind() != Kind.LIST_CONSTRUCTOR_EXPRESSION) {
+            throw new AsterixException("The range hint must be a list.");
+        }
+        List<Expression> el = ((ListConstructor) q.getBody()).getExprList();
+        int offsets[] = new int[el.size()];
+
+        // Loop over list of literals
+        for (int i = 0; i < el.size(); ++i) {
+            Expression item = el.get(i);
+            if (item.getKind() == Kind.LITERAL_EXPRESSION) {
+                parseLiteralToBytes(item, out);
+                offsets[i] = abvs.getLength();
+            }
+            // TODO Add support for composite fields.
+        }
+
+        return new RangeMap(1, abvs.getByteArray(), offsets);
+    }
+
+    @SuppressWarnings("unchecked")
+    private static void parseLiteralToBytes(Expression item, DataOutput out) throws AsterixException {
+        AMutableDouble aDouble = new AMutableDouble(0);
+        AMutableFloat aFloat = new AMutableFloat(0);
+        AMutableInt64 aInt64 = new AMutableInt64(0);
+        AMutableInt32 aInt32 = new AMutableInt32(0);
+        AMutableString aString = new AMutableString("");
+        @SuppressWarnings("rawtypes")
+        ISerializerDeserializer serde;
+
+        Literal l = ((LiteralExpr) item).getValue();
+        try {
+            switch (l.getLiteralType()) {
+                case DOUBLE:
+                    DoubleLiteral dl = (DoubleLiteral) l;
+                    serde = AqlSerializerDeserializerProvider.INSTANCE.getSerializerDeserializer(BuiltinType.ADOUBLE);
+                    aDouble.setValue(dl.getValue());
+                    serde.serialize(aDouble, out);
+                    break;
+                case FLOAT:
+                    FloatLiteral fl = (FloatLiteral) l;
+                    serde = AqlSerializerDeserializerProvider.INSTANCE.getSerializerDeserializer(BuiltinType.AFLOAT);
+                    aFloat.setValue(fl.getValue());
+                    serde.serialize(aFloat, out);
+                    break;
+                case INTEGER:
+                    IntegerLiteral il = (IntegerLiteral) l;
+                    serde = AqlSerializerDeserializerProvider.INSTANCE.getSerializerDeserializer(BuiltinType.AINT32);
+                    aInt32.setValue(il.getValue());
+                    serde.serialize(aInt32, out);
+                    break;
+                case LONG:
+                    LongIntegerLiteral lil = (LongIntegerLiteral) l;
+                    serde = AqlSerializerDeserializerProvider.INSTANCE.getSerializerDeserializer(BuiltinType.AINT64);
+                    aInt64.setValue(lil.getValue());
+                    serde.serialize(aInt64, out);
+                    break;
+                case STRING:
+                    StringLiteral sl = (StringLiteral) l;
+                    serde = AqlSerializerDeserializerProvider.INSTANCE.getSerializerDeserializer(BuiltinType.ASTRING);
+                    aString.setValue(sl.getValue());
+                    serde.serialize(aString, out);
+                    break;
+                default:
+                    throw new NotImplementedException("The range map builder has not been implemented for "
+                            + item.getKind() + " type of expressions.");
+            }
+        } catch (HyracksDataException e) {
+            throw new AsterixException(e.getMessage());
+        }
+    }
+
+    public static void verifyRangeOrder(IRangeMap rangeMap, boolean ascending) throws AsterixException {
+        // TODO Add support for composite fields.
+        int fieldIndex = 0;
+        int fieldType = rangeMap.getTag(0, 0);
+        AqlBinaryComparatorFactoryProvider comparatorFactory = AqlBinaryComparatorFactoryProvider.INSTANCE;
+        IBinaryComparatorFactory bcf = comparatorFactory
+                .getBinaryComparatorFactory(ATypeTag.VALUE_TYPE_MAPPING[fieldType], ascending);
+        IBinaryComparator comparator = bcf.createBinaryComparator();
+        int c = 0;
+        for (int split = 1; split < rangeMap.getSplitCount(); ++split) {
+            if (fieldType != rangeMap.getTag(fieldIndex, split)) {
+                throw new AsterixException("Range field contains more than a single type of items (" + fieldType
+                        + " and " + rangeMap.getTag(fieldIndex, split) + ").");
+            }
+            int previousSplit = split - 1;
+            try {
+                c = comparator.compare(rangeMap.getByteArray(fieldIndex, previousSplit),
+                        rangeMap.getStartOffset(fieldIndex, previousSplit),
+                        rangeMap.getLength(fieldIndex, previousSplit), rangeMap.getByteArray(fieldIndex, split),
+                        rangeMap.getStartOffset(fieldIndex, split), rangeMap.getLength(fieldIndex, split));
+            } catch (HyracksDataException e) {
+                throw new AsterixException(e);
+            }
+            if (c >= 0) {
+                throw new AsterixException("Range fields are not in sorted order.");
+            }
+        }
+    }
+}
diff --git a/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/visitor/AQLCloneAndSubstituteVariablesVisitor.java b/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/visitor/AQLCloneAndSubstituteVariablesVisitor.java
new file mode 100644
index 0000000..511354e
--- /dev/null
+++ b/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/visitor/AQLCloneAndSubstituteVariablesVisitor.java
@@ -0,0 +1,100 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.asterix.lang.aql.visitor;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.apache.asterix.common.exceptions.AsterixException;
+import org.apache.asterix.lang.aql.clause.DistinctClause;
+import org.apache.asterix.lang.aql.clause.ForClause;
+import org.apache.asterix.lang.aql.expression.FLWOGRExpression;
+import org.apache.asterix.lang.aql.expression.UnionExpr;
+import org.apache.asterix.lang.aql.visitor.base.IAQLVisitor;
+import org.apache.asterix.lang.common.base.Clause;
+import org.apache.asterix.lang.common.base.Expression;
+import org.apache.asterix.lang.common.base.ILangExpression;
+import org.apache.asterix.lang.common.expression.VariableExpr;
+import org.apache.asterix.lang.common.rewrites.LangRewritingContext;
+import org.apache.asterix.lang.common.rewrites.VariableSubstitutionEnvironment;
+import org.apache.asterix.lang.common.utils.VariableCloneAndSubstitutionUtil;
+import org.apache.asterix.lang.common.visitor.CloneAndSubstituteVariablesVisitor;
+import org.apache.hyracks.algebricks.common.utils.Pair;
+
+public class AQLCloneAndSubstituteVariablesVisitor extends CloneAndSubstituteVariablesVisitor implements
+        IAQLVisitor<Pair<ILangExpression, VariableSubstitutionEnvironment>, VariableSubstitutionEnvironment> {
+
+    private LangRewritingContext context;
+
+    public AQLCloneAndSubstituteVariablesVisitor(LangRewritingContext context) {
+        super(context);
+        this.context = context;
+    }
+
+    @Override
+    public Pair<ILangExpression, VariableSubstitutionEnvironment> visit(ForClause fc,
+            VariableSubstitutionEnvironment env) throws AsterixException {
+        Pair<ILangExpression, VariableSubstitutionEnvironment> p1 = fc.getInExpr().accept(this, env);
+        VariableExpr varExpr = fc.getVarExpr();
+        VariableExpr newVe = generateNewVariable(context, varExpr);
+        VariableSubstitutionEnvironment resultEnv = new VariableSubstitutionEnvironment(env);
+        resultEnv.removeSubstitution(varExpr);
+
+        VariableExpr posVarExpr = null;
+        if (fc.hasPosVar()) {
+            posVarExpr = fc.getPosVarExpr();
+            resultEnv.removeSubstitution(posVarExpr);
+        }
+        ForClause newFor = new ForClause(newVe, (Expression) p1.first, posVarExpr);
+        return new Pair<ILangExpression, VariableSubstitutionEnvironment>(newFor, resultEnv);
+    }
+
+    @Override
+    public Pair<ILangExpression, VariableSubstitutionEnvironment> visit(FLWOGRExpression flwor,
+            VariableSubstitutionEnvironment env) throws AsterixException {
+        List<Clause> newClauses = new ArrayList<Clause>(flwor.getClauseList().size());
+        VariableSubstitutionEnvironment currentEnv = env;
+        for (Clause c : flwor.getClauseList()) {
+            Pair<ILangExpression, VariableSubstitutionEnvironment> p1 = c.accept(this, currentEnv);
+            currentEnv = p1.second;
+            newClauses.add((Clause) p1.first);
+        }
+        Pair<ILangExpression, VariableSubstitutionEnvironment> p2 = flwor.getReturnExpr().accept(this, currentEnv);
+        Expression newReturnExpr = (Expression) p2.first;
+        FLWOGRExpression newFlwor = new FLWOGRExpression(newClauses, newReturnExpr);
+        return new Pair<ILangExpression, VariableSubstitutionEnvironment>(newFlwor, p2.second);
+    }
+
+    @Override
+    public Pair<ILangExpression, VariableSubstitutionEnvironment> visit(UnionExpr u,
+            VariableSubstitutionEnvironment env) throws AsterixException {
+        List<Expression> exprList = VariableCloneAndSubstitutionUtil.visitAndCloneExprList(u.getExprs(), env, this);
+        UnionExpr newU = new UnionExpr(exprList);
+        return new Pair<ILangExpression, VariableSubstitutionEnvironment>(newU, env);
+    }
+
+    @Override
+    public Pair<ILangExpression, VariableSubstitutionEnvironment> visit(DistinctClause dc,
+            VariableSubstitutionEnvironment env) throws AsterixException {
+        List<Expression> exprList = VariableCloneAndSubstitutionUtil.visitAndCloneExprList(dc.getDistinctByExpr(), env,
+                this);
+        DistinctClause dc2 = new DistinctClause(exprList);
+        return new Pair<ILangExpression, VariableSubstitutionEnvironment>(dc2, env);
+    }
+}
\ No newline at end of file
diff --git a/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/visitor/AQLFormatPrintVisitor.java b/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/visitor/AQLFormatPrintVisitor.java
new file mode 100644
index 0000000..ae186ab
--- /dev/null
+++ b/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/visitor/AQLFormatPrintVisitor.java
@@ -0,0 +1,84 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.asterix.lang.aql.visitor;
+
+import java.io.PrintWriter;
+
+import org.apache.asterix.common.exceptions.AsterixException;
+import org.apache.asterix.lang.aql.clause.DistinctClause;
+import org.apache.asterix.lang.aql.clause.ForClause;
+import org.apache.asterix.lang.aql.expression.FLWOGRExpression;
+import org.apache.asterix.lang.aql.expression.UnionExpr;
+import org.apache.asterix.lang.aql.visitor.base.IAQLVisitor;
+import org.apache.asterix.lang.common.base.Clause;
+import org.apache.asterix.lang.common.visitor.FormatPrintVisitor;
+
+public class AQLFormatPrintVisitor extends FormatPrintVisitor implements IAQLVisitor<Void, Integer> {
+
+    private final PrintWriter out;
+
+    public AQLFormatPrintVisitor() {
+        super();
+        out = new PrintWriter(System.out);
+    }
+
+    public AQLFormatPrintVisitor(PrintWriter out) {
+        super(out);
+        this.out = out;
+    }
+
+    @Override
+    public Void visit(FLWOGRExpression flwor, Integer step) throws AsterixException {
+        for (Clause cl : flwor.getClauseList()) {
+            cl.accept(this, step);
+        }
+        out.print(skip(step) + "return ");
+        flwor.getReturnExpr().accept(this, step + 2);
+        return null;
+    }
+
+    @Override
+    public Void visit(ForClause fc, Integer step) throws AsterixException {
+        out.print("for ");
+        fc.getVarExpr().accept(this, step + 2);
+        if (fc.hasPosVar()) {
+            out.print(" at ");
+            fc.getPosVarExpr().accept(this, step + 2);
+        }
+        out.print(" in ");
+        fc.getInExpr().accept(this, step + 2);
+        out.println();
+        return null;
+    }
+
+    @Override
+    public Void visit(UnionExpr u, Integer step) throws AsterixException {
+        printDelimitedExpressions(u.getExprs(), "\n" + skip(step) + "union\n", step);
+        return null;
+    }
+
+    @Override
+    public Void visit(DistinctClause dc, Integer step) throws AsterixException {
+        out.print(skip(step) + "distinct by ");
+        printDelimitedExpressions(dc.getDistinctByExpr(), COMMA, step + 2);
+        out.println();
+        return null;
+    }
+
+}
diff --git a/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/visitor/AQLInlineUdfsVisitor.java b/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/visitor/AQLInlineUdfsVisitor.java
new file mode 100644
index 0000000..b53d888
--- /dev/null
+++ b/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/visitor/AQLInlineUdfsVisitor.java
@@ -0,0 +1,87 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.asterix.lang.aql.visitor;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.apache.asterix.common.exceptions.AsterixException;
+import org.apache.asterix.lang.aql.clause.DistinctClause;
+import org.apache.asterix.lang.aql.clause.ForClause;
+import org.apache.asterix.lang.aql.expression.FLWOGRExpression;
+import org.apache.asterix.lang.aql.expression.UnionExpr;
+import org.apache.asterix.lang.aql.visitor.base.IAQLVisitor;
+import org.apache.asterix.lang.common.base.Clause;
+import org.apache.asterix.lang.common.base.Expression;
+import org.apache.asterix.lang.common.clause.LetClause;
+import org.apache.asterix.lang.common.rewrites.LangRewritingContext;
+import org.apache.asterix.lang.common.statement.FunctionDecl;
+import org.apache.asterix.lang.common.visitor.AbstractInlineUdfsVisitor;
+import org.apache.hyracks.algebricks.common.utils.Pair;
+
+public class AQLInlineUdfsVisitor extends AbstractInlineUdfsVisitor
+        implements IAQLVisitor<Boolean, List<FunctionDecl>> {
+
+    public AQLInlineUdfsVisitor(LangRewritingContext context) {
+        super(context, new AQLCloneAndSubstituteVariablesVisitor(context));
+    }
+
+    @Override
+    public Boolean visit(FLWOGRExpression flwor, List<FunctionDecl> arg) throws AsterixException {
+        boolean changed = false;
+        for (Clause c : flwor.getClauseList()) {
+            if (c.accept(this, arg)) {
+                changed = true;
+            }
+        }
+        Pair<Boolean, Expression> p = inlineUdfsInExpr(flwor.getReturnExpr(), arg);
+        flwor.setReturnExpr(p.second);
+        return changed || p.first;
+    }
+
+    @Override
+    public Boolean visit(ForClause fc, List<FunctionDecl> arg) throws AsterixException {
+        Pair<Boolean, Expression> p = inlineUdfsInExpr(fc.getInExpr(), arg);
+        fc.setInExpr(p.second);
+        return p.first;
+    }
+
+    @Override
+    public Boolean visit(UnionExpr u, List<FunctionDecl> fds) throws AsterixException {
+        Pair<Boolean, ArrayList<Expression>> p = inlineUdfsInExprList(u.getExprs(), fds);
+        u.setExprs(p.second);
+        return p.first;
+    }
+
+    @Override
+    public Boolean visit(DistinctClause dc, List<FunctionDecl> arg) throws AsterixException {
+        boolean changed = false;
+        for (Expression expr : dc.getDistinctByExpr()) {
+            changed = expr.accept(this, arg);
+        }
+        return changed;
+    }
+
+    @Override
+    protected Expression generateQueryExpression(List<LetClause> letClauses, Expression returnExpr) {
+        List<Clause> letList = new ArrayList<Clause>();
+        letList.addAll(letClauses);
+        return new FLWOGRExpression(letList, returnExpr);
+    }
+}
diff --git a/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/visitor/AQLPrintVisitor.java b/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/visitor/AQLPrintVisitor.java
new file mode 100644
index 0000000..2798ef8
--- /dev/null
+++ b/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/visitor/AQLPrintVisitor.java
@@ -0,0 +1,87 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.asterix.lang.aql.visitor;
+
+import java.io.PrintWriter;
+
+import org.apache.asterix.common.exceptions.AsterixException;
+import org.apache.asterix.lang.aql.clause.DistinctClause;
+import org.apache.asterix.lang.aql.clause.ForClause;
+import org.apache.asterix.lang.aql.expression.FLWOGRExpression;
+import org.apache.asterix.lang.aql.expression.UnionExpr;
+import org.apache.asterix.lang.aql.visitor.base.IAQLVisitor;
+import org.apache.asterix.lang.common.base.Clause;
+import org.apache.asterix.lang.common.base.Expression;
+import org.apache.asterix.lang.common.visitor.QueryPrintVisitor;
+
+public class AQLPrintVisitor extends QueryPrintVisitor implements IAQLVisitor<Void, Integer> {
+
+    private final PrintWriter out;
+
+    public AQLPrintVisitor() {
+        super();
+        out = new PrintWriter(System.out);
+    }
+
+    public AQLPrintVisitor(PrintWriter out) {
+        super(out);
+        this.out = out;
+    }
+
+    @Override
+    public Void visit(FLWOGRExpression flwor, Integer step) throws AsterixException {
+        out.println(skip(step) + "FLWOGR [");
+        for (Clause cl : flwor.getClauseList()) {
+            cl.accept(this, step + 1);
+        }
+        out.println(skip(step + 1) + "Return");
+        flwor.getReturnExpr().accept(this, step + 2);
+        out.println(skip(step) + "]");
+        return null;
+    }
+
+    @Override
+    public Void visit(ForClause fc, Integer step) throws AsterixException {
+        out.print(skip(step) + "For ");
+        fc.getVarExpr().accept(this, 0);
+        out.println(skip(step + 1) + "In ");
+        fc.getInExpr().accept(this, step + 1);
+        return null;
+    }
+
+    @Override
+    public Void visit(UnionExpr u, Integer step) throws AsterixException {
+        out.println(skip(step) + "Union [");
+        for (Expression expr : u.getExprs()) {
+            expr.accept(this, step + 1);
+        }
+        out.println(skip(step) + "]");
+        return null;
+    }
+
+    @Override
+    public Void visit(DistinctClause dc, Integer step) throws AsterixException {
+        out.print(skip(step) + "Distinct ");
+        for (Expression expr : dc.getDistinctByExpr()) {
+            expr.accept(this, step + 1);
+        }
+        return null;
+    }
+
+}
diff --git a/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/visitor/AQLToSQLPPPrintVisitor.java b/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/visitor/AQLToSQLPPPrintVisitor.java
new file mode 100644
index 0000000..ba837b5
--- /dev/null
+++ b/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/visitor/AQLToSQLPPPrintVisitor.java
@@ -0,0 +1,632 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.asterix.lang.aql.visitor;
+
+import java.io.PrintWriter;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+import org.apache.asterix.common.exceptions.AsterixException;
+import org.apache.asterix.common.functions.FunctionSignature;
+import org.apache.asterix.lang.aql.clause.DistinctClause;
+import org.apache.asterix.lang.aql.clause.ForClause;
+import org.apache.asterix.lang.aql.expression.FLWOGRExpression;
+import org.apache.asterix.lang.aql.expression.UnionExpr;
+import org.apache.asterix.lang.aql.util.AQLVariableSubstitutionUtil;
+import org.apache.asterix.lang.aql.visitor.base.IAQLVisitor;
+import org.apache.asterix.lang.common.base.Clause;
+import org.apache.asterix.lang.common.base.Clause.ClauseType;
+import org.apache.asterix.lang.common.base.Expression;
+import org.apache.asterix.lang.common.base.Expression.Kind;
+import org.apache.asterix.lang.common.clause.GroupbyClause;
+import org.apache.asterix.lang.common.clause.LetClause;
+import org.apache.asterix.lang.common.clause.WhereClause;
+import org.apache.asterix.lang.common.expression.CallExpr;
+import org.apache.asterix.lang.common.expression.FieldAccessor;
+import org.apache.asterix.lang.common.expression.GbyVariableExpressionPair;
+import org.apache.asterix.lang.common.expression.LiteralExpr;
+import org.apache.asterix.lang.common.expression.OperatorExpr;
+import org.apache.asterix.lang.common.expression.VariableExpr;
+import org.apache.asterix.lang.common.statement.DataverseDecl;
+import org.apache.asterix.lang.common.statement.DeleteStatement;
+import org.apache.asterix.lang.common.statement.InsertStatement;
+import org.apache.asterix.lang.common.statement.Query;
+import org.apache.asterix.lang.common.struct.Identifier;
+import org.apache.asterix.lang.common.struct.VarIdentifier;
+import org.apache.asterix.lang.common.visitor.FormatPrintVisitor;
+import org.apache.hyracks.algebricks.common.utils.Pair;
+
+public class AQLToSQLPPPrintVisitor extends FormatPrintVisitor implements IAQLVisitor<Void, Integer> {
+
+    private final PrintWriter out;
+    private final Set<String> reservedKeywords = new HashSet<String>();
+    private int generatedId = 0;
+
+    public AQLToSQLPPPrintVisitor() {
+        this(new PrintWriter(System.out));
+    }
+
+    public AQLToSQLPPPrintVisitor(PrintWriter out) {
+        super(out);
+        this.out = out;
+        initialize();
+    }
+
+    private void initialize() {
+        dataverseSymbol = " database ";
+        datasetSymbol = " table ";
+        assignSymbol = "=";
+        reservedKeywords.addAll(Arrays.asList(new String[] { "order", "value", "nest", "keyword", "all" }));
+    }
+
+    @Override
+    public Void visit(FLWOGRExpression flwor, Integer step) throws AsterixException {
+        if (step != 0) {
+            out.println("(");
+        }
+        List<Clause> clauseList = new ArrayList<Clause>();
+        clauseList.addAll(flwor.getClauseList());
+
+        // Processes data-independent let clauses.
+        if (hasFor(clauseList)) {
+            processLeadingLetClauses(step, clauseList);
+        }
+
+        // Distill unnecessary order-bys before a group-by.
+        distillRedundantOrderby(clauseList);
+
+        // Correlated "for" clauses after group-by.
+        Pair<GroupbyClause, List<Clause>> extraction = extractUnnestAfterGroupby(clauseList);
+        GroupbyClause cuttingGbyClause = extraction.first;
+        List<Clause> unnestClauseList = extraction.second;
+        Expression returnExpr = flwor.getReturnExpr();
+        if (unnestClauseList.size() == 0) {
+            if (hasFor(clauseList)) {
+                out.print(skip(step) + "select element ");
+                returnExpr.accept(this, step + 2);
+                out.println();
+            } else {
+                // The FLOWGR only contains let-return, then inline let binding expressions into the return expression.
+                Map<VariableExpr, Expression> varExprMap = extractLetBindingVariables(clauseList, cuttingGbyClause);
+                returnExpr = (Expression) AQLVariableSubstitutionUtil.substituteVariable(returnExpr, varExprMap);
+                returnExpr.accept(this, step);
+                return null;
+            }
+        }
+
+        String generated = generateVariableSymbol();
+        if (unnestClauseList.size() > 0) {
+            Map<VariableExpr, Expression> varExprMap = extractDefinedCollectionVariables(clauseList, cuttingGbyClause,
+                    generated);
+
+            returnExpr = (Expression) AQLVariableSubstitutionUtil.substituteVariable(returnExpr, varExprMap);
+            List<Clause> newUnnestClauses = new ArrayList<Clause>();
+            for (Clause nestedCl : unnestClauseList) {
+                newUnnestClauses.add((Clause) AQLVariableSubstitutionUtil.substituteVariable(nestedCl, varExprMap));
+            }
+            unnestClauseList = newUnnestClauses;
+
+            out.print(skip(step) + "select element " + (hasDistinct(unnestClauseList) ? "distinct " : ""));
+            returnExpr.accept(this, step + 2);
+            out.println();
+            out.println(skip(step) + "from");
+            out.print(skip(step + 2) + "( select element " + (hasDistinct(clauseList) ? "distinct " : "") + "{");
+            int index = 0;
+            int size = varExprMap.size();
+            for (VariableExpr var : varExprMap.keySet()) {
+                out.print("\'" + var.getVar().getValue().substring(1) + "\':" + var.getVar().getValue().substring(1));
+                if (++index < size) {
+                    out.print(COMMA);
+                }
+            }
+            out.println("}");
+        }
+
+        reorder(clauseList);
+        reorder(unnestClauseList);
+
+        mergeConsecutiveWhereClauses(clauseList);
+        mergeConsecutiveWhereClauses(unnestClauseList);
+
+        boolean firstFor = true;
+        boolean firstLet = true;
+        int forStep = unnestClauseList.size() == 0 ? step : step + 3;
+        int size = clauseList.size();
+        // Processes all other clauses, with special printing for consecutive
+        // "for"s.
+        for (int i = 0; i < size; ++i) {
+            Clause cl = clauseList.get(i);
+            if (cl.getClauseType() == ClauseType.FOR_CLAUSE) {
+                boolean hasConsequentFor = false;
+                if (i < size - 1) {
+                    Clause nextCl = clauseList.get(i + 1);
+                    hasConsequentFor = nextCl.getClauseType() == ClauseType.FOR_CLAUSE;
+                }
+                visitForClause((ForClause) cl, forStep, firstFor, hasConsequentFor);
+                firstFor = false;
+            } else if (cl.getClauseType() == ClauseType.LET_CLAUSE) {
+                boolean hasConsequentLet = false;
+                if (i < size - 1) {
+                    Clause nextCl = clauseList.get(i + 1);
+                    hasConsequentLet = nextCl.getClauseType() == ClauseType.LET_CLAUSE;
+                }
+                visitLetClause((LetClause) cl, forStep, firstLet, hasConsequentLet);
+                firstLet = false;
+            } else {
+                cl.accept(this, forStep);
+            }
+
+            if (cl.getClauseType() == ClauseType.FROM_CLAUSE || cl.getClauseType() == ClauseType.GROUP_BY_CLAUSE) {
+                firstLet = true;
+            }
+        }
+
+        if (unnestClauseList.size() > 0) {
+            out.println(skip(forStep - 1) + ") as " + generated.substring(1) + ",");
+            for (Clause nestedCl : unnestClauseList) {
+                if (nestedCl.getClauseType() == ClauseType.FOR_CLAUSE) {
+                    visitForClause((ForClause) nestedCl, step - 1, firstFor, false);
+                } else {
+                    nestedCl.accept(this, step);
+                }
+            }
+        }
+
+        if (step > 0) {
+            out.print(skip(step - 2) + ")");
+        }
+        return null;
+    }
+
+    @Override
+    public Void visit(ForClause fc, Integer step) throws AsterixException {
+        // The processing of a "for" clause depends on its neighbor clauses,
+        // hence the logic goes to visit(FLWOGRExpression).
+        return null;
+    }
+
+    private void visitForClause(ForClause fc, Integer step, boolean startFor, boolean hasConsequentFor)
+            throws AsterixException {
+        if (startFor) {
+            out.print(skip(step) + "from  ");
+        } else {
+            out.print(skip(step + 3));
+        }
+        fc.getInExpr().accept(this, step + 2);
+        out.print(" as ");
+        fc.getVarExpr().accept(this, step + 2);
+        if (fc.hasPosVar()) {
+            out.print(" at ");
+            fc.getPosVarExpr().accept(this, step + 2);
+        }
+        if (hasConsequentFor) {
+            out.print(COMMA);
+        }
+        out.println();
+    }
+
+    private void visitLetClause(LetClause lc, Integer step, boolean startLet, boolean hasConsequentLet)
+            throws AsterixException {
+        if (startLet) {
+            out.print(skip(step) + "with  ");
+        } else {
+            out.print(skip(step + 3));
+        }
+        lc.getVarExpr().accept(this, step + 3);
+        out.print(" as ");
+        lc.getBindingExpr().accept(this, step + 3);
+        if (hasConsequentLet) {
+            out.print(COMMA);
+        }
+        out.println();
+    }
+
+    @Override
+    public Void visit(Query q, Integer step) throws AsterixException {
+        Expression expr = q.getBody();
+        if (expr != null) {
+            if (expr.getKind() != Kind.FLWOGR_EXPRESSION) {
+                out.print("select element ");
+                expr.accept(this, step + 2);
+            } else {
+                expr.accept(this, step);
+            }
+        }
+        if (q.isTopLevel()) {
+            out.println(SEMICOLON);
+        }
+        return null;
+    }
+
+    @Override
+    public Void visit(DataverseDecl dv, Integer step) throws AsterixException {
+        out.println(skip(step) + "use " + normalize(dv.getDataverseName().getValue()) + ";\n\n");
+        return null;
+    }
+
+    @Override
+    public Void visit(UnionExpr u, Integer step) throws AsterixException {
+        printDelimitedExpressions(u.getExprs(), "\n" + skip(step) + "union\n" + skip(step), step);
+        return null;
+    }
+
+    @Override
+    public Void visit(DistinctClause dc, Integer step) throws AsterixException {
+        return null;
+    }
+
+    @Override
+    public Void visit(VariableExpr v, Integer step) {
+        String varStr = v.getVar().getValue().substring(1);
+        if (reservedKeywords.contains(varStr)) {
+            varStr = varStr + "s";
+        }
+        out.print(varStr);
+        return null;
+    }
+
+    @Override
+    public Void visit(LetClause lc, Integer step) throws AsterixException {
+        out.print(skip(step) + "with ");
+        lc.getVarExpr().accept(this, step + 2);
+        out.print(" as ");
+        Expression bindingExpr = lc.getBindingExpr();
+        bindingExpr.accept(this, step + 2);
+        out.println();
+        return null;
+    }
+
+    @Override
+    public Void visit(CallExpr callExpr, Integer step) throws AsterixException {
+        FunctionSignature signature = callExpr.getFunctionSignature();
+        if (signature.getNamespace() != null && signature.getNamespace().equals("Metadata")
+                && signature.getName().equals("dataset") && signature.getArity() == 1) {
+            LiteralExpr expr = (LiteralExpr) callExpr.getExprList().get(0);
+            out.print(normalize(expr.getValue().getStringValue()));
+        } else {
+            printHints(callExpr.getHints(), step);
+            out.print(generateFullName(callExpr.getFunctionSignature().getNamespace(),
+                    callExpr.getFunctionSignature().getName()) + "(");
+            printDelimitedExpressions(callExpr.getExprList(), COMMA, step);
+            out.print(")");
+        }
+        return null;
+    }
+
+    @Override
+    public Void visit(GroupbyClause gc, Integer step) throws AsterixException {
+        if (gc.hasHashGroupByHint()) {
+            out.println(skip(step) + "/* +hash */");
+        }
+        out.print(skip(step) + "group by ");
+        printDelimitedGbyExpressions(gc.getGbyPairList(), step + 2);
+        out.println();
+        return null;
+    }
+
+    @Override
+    public Void visit(InsertStatement insert, Integer step) throws AsterixException {
+        out.print(skip(step) + "insert into " + generateFullName(insert.getDataverseName(), insert.getDatasetName())
+                + "\n");
+        insert.getQuery().accept(this, step);
+        out.println(SEMICOLON);
+        return null;
+    }
+
+    @Override
+    public Void visit(DeleteStatement del, Integer step) throws AsterixException {
+        out.print(skip(step) + "delete ");
+        del.getVariableExpr().accept(this, step + 2);
+        out.println(skip(step) + " from " + generateFullName(del.getDataverseName(), del.getDatasetName()));
+        if (del.getCondition() != null) {
+            out.print(skip(step) + " where ");
+            del.getCondition().accept(this, step + 2);
+        }
+        out.println(SEMICOLON);
+        return null;
+    }
+
+    @Override
+    protected String normalize(String str) {
+        if (needQuotes(str) || containsReservedKeyWord(str.toLowerCase())) {
+            return revertStringToQuoted(str);
+        }
+        return str;
+    }
+
+    protected boolean containsReservedKeyWord(String str) {
+        if (reservedKeywords.contains(str)) {
+            return true;
+        }
+        return false;
+    }
+
+    @Override
+    protected void printDelimitedGbyExpressions(List<GbyVariableExpressionPair> gbyList, int step)
+            throws AsterixException {
+        int gbySize = gbyList.size();
+        int gbyIndex = 0;
+        for (GbyVariableExpressionPair pair : gbyList) {
+            pair.getExpr().accept(this, step);
+            if (pair.getVar() != null) {
+                out.print(" as ");
+                pair.getVar().accept(this, step);
+            }
+            if (++gbyIndex < gbySize) {
+                out.print(COMMA);
+            }
+        }
+    }
+
+    @Override
+    protected void printDelimitedIdentifiers(List<Identifier> ids, String delimiter) {
+        int index = 0;
+        int size = ids.size();
+        for (Identifier id : ids) {
+            String idStr = id.getValue();
+            if (idStr.startsWith("$")) {
+                id = new Identifier(idStr.substring(1));
+            }
+            out.print(id);
+            if (++index < size) {
+                out.print(delimiter);
+            }
+        }
+    }
+
+    // Collects produced variables from group-by.
+    private List<VariableExpr> collectProducedVariablesFromGroupby(GroupbyClause gbyClause) {
+        List<VariableExpr> producedVars = new ArrayList<VariableExpr>();
+        for (GbyVariableExpressionPair keyPair : gbyClause.getGbyPairList()) {
+            producedVars.add(keyPair.getVar());
+        }
+        for (GbyVariableExpressionPair keyPair : gbyClause.getDecorPairList()) {
+            producedVars.add(keyPair.getVar());
+        }
+        producedVars.addAll(gbyClause.getWithVarList());
+        return producedVars;
+    }
+
+    // Randomly generates a new variable symbol.
+    private String generateVariableSymbol() {
+        return "$gen" + generatedId++;
+    }
+
+    // Removes all redundant order by clauses.
+    private void distillRedundantOrderby(List<Clause> clauseList) {
+        List<Clause> redundantOrderbys = new ArrayList<Clause>();
+        boolean gbyAfterOrderby = false;
+        for (Clause cl : clauseList) {
+            if (cl.getClauseType() == ClauseType.ORDER_BY_CLAUSE) {
+                redundantOrderbys.add(cl);
+            }
+            if (cl.getClauseType() == ClauseType.GROUP_BY_CLAUSE) {
+                gbyAfterOrderby = true;
+                break;
+            }
+        }
+        if (gbyAfterOrderby) {
+            clauseList.removeAll(redundantOrderbys);
+        }
+
+        redundantOrderbys.clear();
+        for (Clause cl : clauseList) {
+            if (cl.getClauseType() == ClauseType.ORDER_BY_CLAUSE) {
+                redundantOrderbys.add(cl);
+            }
+        }
+        if (redundantOrderbys.size() > 0) {
+            redundantOrderbys.remove(redundantOrderbys.size() - 1);
+        }
+        clauseList.removeAll(redundantOrderbys);
+    }
+
+    // Processes leading "let"s in a FLWOGR.
+    private void processLeadingLetClauses(Integer step, List<Clause> clauseList) throws AsterixException {
+        List<Clause> processedLetList = new ArrayList<Clause>();
+        boolean firstLet = true;
+        int size = clauseList.size();
+        for (int i = 0; i < size; ++i) {
+            Clause cl = clauseList.get(i);
+            if (cl.getClauseType() != ClauseType.LET_CLAUSE) {
+                break;
+            }
+            boolean hasConsequentLet = false;
+            if (i < size - 1) {
+                Clause nextCl = clauseList.get(i + 1);
+                hasConsequentLet = nextCl.getClauseType() == ClauseType.LET_CLAUSE;
+            }
+            visitLetClause((LetClause) cl, step, firstLet, hasConsequentLet);
+            firstLet = false;
+            processedLetList.add(cl);
+        }
+        clauseList.removeAll(processedLetList);
+    }
+
+    // Extracts all clauses that led by a "for" clause after the first group-by
+    // clause in the input clause list.
+    // Those extracted clauses will be removed from the input clause list.
+    /**
+     * @param clauseList
+     *            , a list of clauses
+     * @return the cutting group-by clause and the list of extracted clauses.
+     * @throws AsterixException
+     */
+    private Pair<GroupbyClause, List<Clause>> extractUnnestAfterGroupby(List<Clause> clauseList)
+            throws AsterixException {
+        List<Clause> nestedClauses = new ArrayList<Clause>();
+        GroupbyClause cuttingGbyClause = null;
+        boolean meetGroupBy = false;
+        boolean nestedClauseStarted = false;
+        for (Clause cl : clauseList) {
+            if (cl.getClauseType() == ClauseType.GROUP_BY_CLAUSE) {
+                meetGroupBy = true;
+                cuttingGbyClause = (GroupbyClause) cl;
+                continue;
+            }
+            if (meetGroupBy && cl.getClauseType() == ClauseType.FOR_CLAUSE) {
+                nestedClauseStarted = true;
+            }
+            if (nestedClauseStarted) {
+                nestedClauses.add(cl);
+            }
+        }
+        clauseList.removeAll(nestedClauses);
+        return new Pair<GroupbyClause, List<Clause>>(cuttingGbyClause, nestedClauses);
+    }
+
+    // Extracts the variables to be substituted with a path access.
+    private Map<VariableExpr, Expression> extractDefinedCollectionVariables(List<Clause> clauses,
+            GroupbyClause cuttingGbyClause, String generatedAlias) {
+        Map<VariableExpr, Expression> varExprMap = new HashMap<VariableExpr, Expression>();
+        List<VariableExpr> varToSubstitute = collectProducedVariablesFromGroupby(cuttingGbyClause);
+        int gbyIndex = clauses.indexOf(cuttingGbyClause);
+        for (int i = gbyIndex + 1; i < clauses.size(); i++) {
+            Clause cl = clauses.get(i);
+            if (cl.getClauseType() == ClauseType.LET_CLAUSE) {
+                varToSubstitute.add(((LetClause) cl).getVarExpr());
+            }
+        }
+        for (VariableExpr var : varToSubstitute) {
+            varExprMap.put(var, new FieldAccessor(new VariableExpr(new VarIdentifier(generatedAlias)),
+                    new VarIdentifier(var.getVar().getValue().substring(1))));
+        }
+        return varExprMap;
+    }
+
+    // Extracts the variables to be substituted.
+    private Map<VariableExpr, Expression> extractLetBindingVariables(List<Clause> clauses,
+            GroupbyClause cuttingGbyClause) throws AsterixException {
+        Map<VariableExpr, Expression> varExprMap = new HashMap<VariableExpr, Expression>();
+        int gbyIndex = clauses.indexOf(cuttingGbyClause);
+        for (int i = gbyIndex + 1; i < clauses.size(); i++) {
+            Clause cl = clauses.get(i);
+            if (cl.getClauseType() == ClauseType.LET_CLAUSE) {
+                LetClause letClause = (LetClause) cl;
+                // inline let variables one by one iteratively.
+                letClause.setBindingExpr((Expression) AQLVariableSubstitutionUtil
+                        .substituteVariable(letClause.getBindingExpr(), varExprMap));
+                varExprMap.put(letClause.getVarExpr(), letClause.getBindingExpr());
+            }
+        }
+        return varExprMap;
+    }
+
+    // Re-order clauses.
+    private List<Clause> reorder(List<Clause> clauses) {
+        Comparator<Clause> comparator = new ClauseComparator();
+        List<Clause> results = new ArrayList<Clause>();
+        int size = clauses.size();
+        int start = 0;
+        for (int index = 0; index < size; ++index) {
+            Clause clause = clauses.get(index);
+            if (clause.getClauseType() == ClauseType.GROUP_BY_CLAUSE) {
+                List<Clause> subList = clauses.subList(start, index);
+                Collections.sort(subList, comparator);
+                results.addAll(subList);
+                results.add(clause);
+                start = index + 1;
+            }
+        }
+        if (start < clauses.size()) {
+            List<Clause> subList = clauses.subList(start, size);
+            Collections.sort(subList, comparator);
+            results.addAll(subList);
+        }
+        return results;
+    }
+
+    // Merge consecutive "where" clauses.
+    private void mergeConsecutiveWhereClauses(List<Clause> clauses) {
+        List<Clause> results = new ArrayList<Clause>();
+        int size = clauses.size();
+        for (int index = 0; index < size;) {
+            Clause clause = clauses.get(index);
+            if (clause.getClauseType() != ClauseType.WHERE_CLAUSE) {
+                results.add(clause);
+                ++index;
+            } else {
+                List<Expression> expressions = new ArrayList<Expression>();
+                Clause firstWhereClause = clause;
+                do {
+                    WhereClause whereClause = (WhereClause) clause;
+                    expressions.add(whereClause.getWhereExpr());
+                    if (++index >= size) {
+                        break;
+                    }
+                    clause = clauses.get(index);
+                } while (clause.getClauseType() == ClauseType.WHERE_CLAUSE);
+                if (expressions.size() > 1) {
+                    OperatorExpr newWhereExpr = new OperatorExpr();
+                    newWhereExpr.setExprList(expressions);
+                    newWhereExpr.setCurrentop(true);
+                    for (int operatorIndex = 0; operatorIndex < expressions.size(); ++operatorIndex) {
+                        newWhereExpr.addOperator("and");
+                    }
+                    results.add(new WhereClause(newWhereExpr));
+                } else {
+                    results.add(firstWhereClause);
+                }
+            }
+        }
+        clauses.clear();
+        clauses.addAll(results);
+    }
+
+    // Where there is a distinct clause.
+    protected boolean hasDistinct(List<Clause> clauses) {
+        for (Clause clause : clauses) {
+            if (clause.getClauseType() == ClauseType.DISTINCT_BY_CLAUSE) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    // Whether the list of clauses contains a for clause.
+    private boolean hasFor(List<Clause> clauses) {
+        for (Clause cl : clauses) {
+            if (cl.getClauseType() == ClauseType.FOR_CLAUSE) {
+                return true;
+            }
+        }
+        return false;
+    }
+}
+
+/**
+ * This comparator is used to safely mutate the order of clauses in a FLWOGR
+ * expression. Note: clauses before and after a group-by cannot be re-aligned.
+ */
+class ClauseComparator implements Comparator<Clause> {
+
+    @Override
+    public int compare(Clause left, Clause right) {
+        int ordinalLeft = left.getClauseType().ordinal();
+        int ordinalRight = right.getClauseType().ordinal();
+        return ordinalLeft > ordinalRight ? 1 : (ordinalLeft == ordinalRight ? 0 : -1);
+    }
+}
diff --git a/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/visitor/base/AbstractAqlQueryExpressionVisitor.java b/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/visitor/base/AbstractAqlQueryExpressionVisitor.java
new file mode 100644
index 0000000..977c3b1
--- /dev/null
+++ b/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/visitor/base/AbstractAqlQueryExpressionVisitor.java
@@ -0,0 +1,26 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.asterix.lang.aql.visitor.base;
+
+import org.apache.asterix.lang.common.visitor.base.AbstractQueryExpressionVisitor;
+
+public abstract class AbstractAqlQueryExpressionVisitor<R, T> extends AbstractQueryExpressionVisitor<R, T>
+        implements IAQLVisitor<R, T> {
+
+}
diff --git a/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/visitor/base/IAQLPlusVisitor.java b/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/visitor/base/IAQLPlusVisitor.java
new file mode 100644
index 0000000..f2037e7
--- /dev/null
+++ b/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/visitor/base/IAQLPlusVisitor.java
@@ -0,0 +1,33 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.asterix.lang.aql.visitor.base;
+
+import org.apache.asterix.common.exceptions.AsterixException;
+import org.apache.asterix.lang.aql.clause.JoinClause;
+import org.apache.asterix.lang.aql.clause.MetaVariableClause;
+import org.apache.asterix.lang.aql.expression.MetaVariableExpr;
+
+public interface IAQLPlusVisitor<R, T> extends IAQLVisitor<R, T> {
+
+    R visitJoinClause(JoinClause c, T arg) throws AsterixException;
+
+    R visitMetaVariableClause(MetaVariableClause c, T arg) throws AsterixException;
+
+    R visitMetaVariableExpr(MetaVariableExpr v, T arg) throws AsterixException;
+}
diff --git a/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/visitor/base/IAQLVisitor.java b/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/visitor/base/IAQLVisitor.java
new file mode 100644
index 0000000..d990005
--- /dev/null
+++ b/asterix-lang-aql/src/main/java/org/apache/asterix/lang/aql/visitor/base/IAQLVisitor.java
@@ -0,0 +1,38 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.asterix.lang.aql.visitor.base;
+
+import org.apache.asterix.common.exceptions.AsterixException;
+import org.apache.asterix.lang.aql.clause.DistinctClause;
+import org.apache.asterix.lang.aql.clause.ForClause;
+import org.apache.asterix.lang.aql.expression.FLWOGRExpression;
+import org.apache.asterix.lang.aql.expression.UnionExpr;
+import org.apache.asterix.lang.common.visitor.base.ILangVisitor;
+
+public interface IAQLVisitor<R, T> extends ILangVisitor<R, T> {
+
+    R visit(FLWOGRExpression flwogreExpr, T arg) throws AsterixException;
+
+    R visit(UnionExpr u, T arg) throws AsterixException;
+
+    R visit(ForClause forClause, T arg) throws AsterixException;
+
+    R visit(DistinctClause distinctClause, T arg) throws AsterixException;
+
+}
diff --git a/asterix-lang-aql/src/main/javacc/AQL.html b/asterix-lang-aql/src/main/javacc/AQL.html
new file mode 100644
index 0000000..b50d554
--- /dev/null
+++ b/asterix-lang-aql/src/main/javacc/AQL.html
@@ -0,0 +1,774 @@
+<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2//EN">
+<HTML>
+<HEAD>
+<TITLE>BNF for AQL.jj</TITLE>
+</HEAD>
+<BODY>
+<H1 ALIGN=CENTER>BNF for AQL.jj</H1>
+<H2 ALIGN=CENTER>TOKENS</H2>
+<TABLE>
+ <!-- Token -->
+ <TR>
+  <TD>
+   <PRE>
+&lt;DEFAULT,IN_DBL_BRACE&gt; TOKEN : {
+&lt;ASC: "asc"&gt;
+| &lt;AT: "at"&gt;
+| &lt;BY: "by"&gt;
+| &lt;DATASET: "dataset"&gt;
+| &lt;DECOR: "decor"&gt;
+| &lt;DESC: "desc"&gt;
+| &lt;DISTINCT: "distinct"&gt;
+| &lt;ELSE: "else"&gt;
+| &lt;EVERY: "every"&gt;
+| &lt;FOR: "for"&gt;
+| &lt;FROM: "from"&gt;
+| &lt;GROUP: "group"&gt;
+| &lt;IF: "if"&gt;
+| &lt;IN: "in"&gt;
+| &lt;LET: "let"&gt;
+| &lt;LIMIT: "limit"&gt;
+| &lt;OFFSET: "offset"&gt;
+| &lt;ORDER: "order"&gt;
+| &lt;RETURN: "return"&gt;
+| &lt;SATISFIES: "satisfies"&gt;
+| &lt;SELECT: "select"&gt;
+| &lt;SOME: "some"&gt;
+| &lt;THEN: "then"&gt;
+| &lt;UNION: "union"&gt;
+| &lt;WHERE: "where"&gt;
+| &lt;WITH: "with"&gt;
+| &lt;KEEPING: "keeping"&gt;
+}
+
+   </PRE>
+  </TD>
+ </TR>
+ <!-- Token -->
+ <TR>
+  <TD>
+   <PRE>
+&lt;DEFAULT,IN_DBL_BRACE&gt; TOKEN : {
+&lt;CARET: "^"&gt;
+| &lt;DIV: "/"&gt;
+| &lt;IDIV: "idiv"&gt;
+| &lt;MINUS: "-"&gt;
+| &lt;MOD: "%"&gt;
+| &lt;MUL: "*"&gt;
+| &lt;PLUS: "+"&gt;
+| &lt;LEFTPAREN: "("&gt;
+| &lt;RIGHTPAREN: ")"&gt;
+| &lt;LEFTBRACKET: "["&gt;
+| &lt;RIGHTBRACKET: "]"&gt;
+| &lt;COLON: ":"&gt;
+| &lt;COMMA: ","&gt;
+| &lt;DOT: "."&gt;
+| &lt;QUES: "?"&gt;
+| &lt;LT: "&lt;"&gt;
+| &lt;GT: "&gt;"&gt;
+| &lt;LE: "&lt;="&gt;
+| &lt;GE: "&gt;="&gt;
+| &lt;EQ: "="&gt;
+| &lt;NE: "!="&gt;
+| &lt;SIMILAR: "~="&gt;
+| &lt;ASSIGN: ":="&gt;
+| &lt;AND: "and"&gt;
+| &lt;OR: "or"&gt;
+}
+
+   </PRE>
+  </TD>
+ </TR>
+ <!-- Token -->
+ <TR>
+  <TD>
+   <PRE>
+&lt;DEFAULT,IN_DBL_BRACE&gt; TOKEN : {
+&lt;LEFTBRACE: "{"&gt; : DEFAULT
+}
+
+   </PRE>
+  </TD>
+ </TR>
+ <!-- Token -->
+ <TR>
+  <TD>
+   <PRE>
+&lt;DEFAULT&gt; TOKEN : {
+&lt;RIGHTBRACE: "}"&gt; : {
+}
+
+   </PRE>
+  </TD>
+ </TR>
+ <!-- Token -->
+ <TR>
+  <TD>
+   <PRE>
+&lt;DEFAULT,IN_DBL_BRACE&gt; TOKEN : {
+&lt;LEFTDBLBRACE: "{{"&gt; : IN_DBL_BRACE
+}
+
+   </PRE>
+  </TD>
+ </TR>
+ <!-- Token -->
+ <TR>
+  <TD>
+   <PRE>
+&lt;IN_DBL_BRACE&gt; TOKEN : {
+&lt;RIGHTDBLBRACE: "}}"&gt; : {
+}
+
+   </PRE>
+  </TD>
+ </TR>
+ <!-- Token -->
+ <TR>
+  <TD>
+   <PRE>
+&lt;DEFAULT,IN_DBL_BRACE&gt; TOKEN : {
+&lt;INTEGER_LITERAL: (&lt;DIGIT&gt;)+&gt;
+}
+
+   </PRE>
+  </TD>
+ </TR>
+ <!-- Token -->
+ <TR>
+  <TD>
+   <PRE>
+&lt;DEFAULT,IN_DBL_BRACE&gt; TOKEN : {
+&lt;NULL: "null"&gt;
+| &lt;TRUE: "true"&gt;
+| &lt;FALSE: "false"&gt;
+}
+
+   </PRE>
+  </TD>
+ </TR>
+ <!-- Token -->
+ <TR>
+  <TD>
+   <PRE>
+&lt;DEFAULT,IN_DBL_BRACE&gt; TOKEN : {
+&lt;#DIGIT: ["0"-"9"]&gt;
+}
+
+   </PRE>
+  </TD>
+ </TR>
+ <!-- Token -->
+ <TR>
+  <TD>
+   <PRE>
+&lt;DEFAULT,IN_DBL_BRACE&gt; TOKEN : {
+&lt;DOUBLE_LITERAL: &lt;DIGITS&gt; | &lt;DIGITS&gt; ("." &lt;DIGITS&gt;)? | "." &lt;DIGITS&gt;&gt;
+| &lt;FLOAT_LITERAL: &lt;DIGITS&gt; ("f" | "F") | &lt;DIGITS&gt; ("." &lt;DIGITS&gt; ("f" | "F"))? | "." &lt;DIGITS&gt; ("f" | "F")&gt;
+| &lt;DIGITS: (&lt;DIGIT&gt;)+&gt;
+}
+
+   </PRE>
+  </TD>
+ </TR>
+ <!-- Token -->
+ <TR>
+  <TD>
+   <PRE>
+&lt;DEFAULT,IN_DBL_BRACE&gt; TOKEN : {
+&lt;#LETTER: ["A"-"Z","a"-"z"]&gt;
+| &lt;SPECIALCHARS: ["$","_","-"]&gt;
+}
+
+   </PRE>
+  </TD>
+ </TR>
+ <!-- Token -->
+ <TR>
+  <TD>
+   <PRE>
+&lt;DEFAULT,IN_DBL_BRACE&gt; TOKEN : {
+&lt;STRING_LITERAL: "\"" (&lt;EscapeQuot&gt; | &lt;EscapeBslash&gt; | &lt;EscapeSlash&gt; | &lt;EscapeBspace&gt; | &lt;EscapeFormf&gt; | &lt;EscapeNl&gt; | &lt;EscapeCr&gt; | &lt;EscapeTab&gt; | ~["\"","\\"])* "\"" | "\'" (&lt;EscapeApos&gt; | &lt;EscapeBslash&gt; | &lt;EscapeSlash&gt; | &lt;EscapeBspace&gt; | &lt;EscapeFormf&gt; | &lt;EscapeNl&gt; | &lt;EscapeCr&gt; | &lt;EscapeTab&gt; | ~["\'","\\"])* "\'"&gt;
+| &lt;#EscapeQuot: "\\\""&gt;
+| &lt;#EscapeApos: "\\\'"&gt;
+| &lt;#EscapeBslash: "\\\\"&gt;
+| &lt;#EscapeSlash: "\\/"&gt;
+| &lt;#EscapeBspace: "\\b"&gt;
+| &lt;#EscapeFormf: "\\f"&gt;
+| &lt;#EscapeNl: "\\n"&gt;
+| &lt;#EscapeCr: "\\r"&gt;
+| &lt;#EscapeTab: "\\t"&gt;
+}
+
+   </PRE>
+  </TD>
+ </TR>
+ <!-- Token -->
+ <TR>
+  <TD>
+   <PRE>
+&lt;DEFAULT,IN_DBL_BRACE&gt; TOKEN : {
+&lt;IDENTIFIER: &lt;LETTER&gt; (&lt;LETTER&gt; | &lt;DIGIT&gt; | &lt;SPECIALCHARS&gt;)*&gt;
+}
+
+   </PRE>
+  </TD>
+ </TR>
+ <!-- Token -->
+ <TR>
+  <TD>
+   <PRE>
+&lt;DEFAULT,IN_DBL_BRACE&gt; TOKEN : {
+&lt;VARIABLE: "$" &lt;LETTER&gt; (&lt;LETTER&gt; | &lt;DIGIT&gt; | "_")*&gt;
+}
+
+   </PRE>
+  </TD>
+ </TR>
+ <!-- Token -->
+ <TR>
+  <TD>
+   <PRE>
+&lt;DEFAULT,IN_DBL_BRACE&gt; SKIP : {
+" "
+| "\t"
+| "\r"
+| "\n"
+}
+
+   </PRE>
+  </TD>
+ </TR>
+ <!-- Token -->
+ <TR>
+  <TD>
+   <PRE>
+&lt;DEFAULT,IN_DBL_BRACE&gt; SKIP : {
+&lt;"//" (~["\n"])* "\n"&gt;
+}
+
+   </PRE>
+  </TD>
+ </TR>
+ <!-- Token -->
+ <TR>
+  <TD>
+   <PRE>
+&lt;DEFAULT,IN_DBL_BRACE&gt; SKIP : {
+&lt;"//" (~["\n","\r"])* ("\n" | "\r" | "\r\n")?&gt;
+}
+
+   </PRE>
+  </TD>
+ </TR>
+ <!-- Token -->
+ <TR>
+  <TD>
+   <PRE>
+&lt;DEFAULT,IN_DBL_BRACE&gt; SKIP : {
+"/*" : INSIDE_COMMENT
+}
+
+   </PRE>
+  </TD>
+ </TR>
+ <!-- Token -->
+ <TR>
+  <TD>
+   <PRE>
+&lt;INSIDE_COMMENT&gt; SPECIAL : {
+&lt;"+" (" ")* (~["*"])*&gt;
+}
+
+   </PRE>
+  </TD>
+ </TR>
+ <!-- Token -->
+ <TR>
+  <TD>
+   <PRE>
+&lt;INSIDE_COMMENT&gt; SKIP : {
+"/*" : {
+}
+
+   </PRE>
+  </TD>
+ </TR>
+ <!-- Token -->
+ <TR>
+  <TD>
+   <PRE>
+&lt;INSIDE_COMMENT&gt; SKIP : {
+"*/" : {
+| &lt;~[]&gt;
+}
+
+   </PRE>
+  </TD>
+ </TR>
+</TABLE>
+<H2 ALIGN=CENTER>NON-TERMINALS</H2>
+<TABLE>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod1">Statement</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>( <A HREF="#prod2">SingleStatement</A> ( ";" )? )* &lt;EOF&gt;</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod2">SingleStatement</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>( <A HREF="#prod3">DataverseDeclaration</A> | <A HREF="#prod4">FunctionDeclaration</A> | <A HREF="#prod5">CreateStatement</A> | <A HREF="#prod6">LoadStatement</A> | <A HREF="#prod7">DropStatement</A> | <A HREF="#prod8">WriteStatement</A> | <A HREF="#prod9">SetStatement</A> | <A HREF="#prod10">InsertStatement</A> | <A HREF="#prod11">DeleteStatement</A> | <A HREF="#prod12">UpdateStatement</A> | <A HREF="#prod13">FeedStatement</A> | <A HREF="#prod14">CompactStatement</A> | <A HREF="#prod15">Query</A> | <A HREF="#prod16">RefreshExternalDatasetStatement</A> | <A HREF="#prod17">RunStatement</A> )</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod3">DataverseDeclaration</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>"use" "dataverse" <A HREF="#prod18">Identifier</A></TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod5">CreateStatement</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>"create" ( <A HREF="#prod19">TypeSpecification</A> | <A HREF="#prod20">NodegroupSpecification</A> | <A HREF="#prod21">DatasetSpecification</A> | <A HREF="#prod22">IndexSpecification</A> | <A HREF="#prod23">DataverseSpecification</A> | <A HREF="#prod24">FunctionSpecification</A> | <A HREF="#prod25">FeedSpecification</A> | <A HREF="#prod26">FeedPolicySpecification</A> )</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod19">TypeSpecification</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>"type" <A HREF="#prod27">TypeName</A> <A HREF="#prod28">IfNotExists</A> "as" <A HREF="#prod29">TypeExpr</A></TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod20">NodegroupSpecification</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>"nodegroup" <A HREF="#prod18">Identifier</A> <A HREF="#prod28">IfNotExists</A> "on" <A HREF="#prod18">Identifier</A> ( &lt;COMMA&gt; <A HREF="#prod18">Identifier</A> )*</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod21">DatasetSpecification</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>( "external" &lt;DATASET&gt; <A HREF="#prod30">QualifiedName</A> &lt;LEFTPAREN&gt; <A HREF="#prod18">Identifier</A> &lt;RIGHTPAREN&gt; <A HREF="#prod28">IfNotExists</A> "using" <A HREF="#prod31">AdapterName</A> <A HREF="#prod32">Configuration</A> ( "on" <A HREF="#prod18">Identifier</A> )? ( "hints" <A HREF="#prod33">Properties</A> )? ( "using" "compaction" "policy" <A HREF="#prod34">CompactionPolicy</A> ( <A HREF="#prod32">Configuration</A> )? )? | ( "internal" | "temporary" )? &lt;DATASET&gt; <A HREF="#prod30">QualifiedName</A> &lt;LEFTPAREN&gt; <A HREF="#prod18">Identifier</A> &lt;RIGHTPAREN&gt; <A HREF="#prod28">IfNotExists</A> <A HREF="#prod35">PrimaryKey</A> ( "autogenerated" )? ( "on" <A HREF="#prod18">Identifier</A> )? ( "hints" <A HREF="#prod33">Properties</A> )? ( "using" "compaction" "policy" <A HREF="#prod34">CompactionPolicy</A> ( <A HREF="#prod32">Configuration</A> )? )? ( "with filter on" <A HREF="#prod36">NestedField</A> )? )</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod16">RefreshExternalDatasetStatement</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>"refresh external" &lt;DATASET&gt; <A HREF="#prod30">QualifiedName</A></TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod17">RunStatement</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>"run" <A HREF="#prod18">Identifier</A> &lt;LEFTPAREN&gt; ( <A HREF="#prod18">Identifier</A> ( &lt;COMMA&gt; )? )* &lt;RIGHTPAREN&gt; &lt;FROM&gt; &lt;DATASET&gt; <A HREF="#prod30">QualifiedName</A> "to" &lt;DATASET&gt; <A HREF="#prod30">QualifiedName</A></TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod22">IndexSpecification</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>"index" <A HREF="#prod18">Identifier</A> <A HREF="#prod28">IfNotExists</A> "on" <A HREF="#prod30">QualifiedName</A> &lt;LEFTPAREN&gt; ( <A HREF="#prod37">OpenField</A> ) ( &lt;COMMA&gt; <A HREF="#prod37">OpenField</A> )* &lt;RIGHTPAREN&gt; ( "type" <A HREF="#prod38">IndexType</A> )? ( "enforced" )?</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod34">CompactionPolicy</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE><A HREF="#prod18">Identifier</A></TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod39">FilterField</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE><A HREF="#prod18">Identifier</A></TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod38">IndexType</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>( "btree" | "rtree" | "keyword" | "ngram" &lt;LEFTPAREN&gt; &lt;INTEGER_LITERAL&gt; &lt;RIGHTPAREN&gt; )</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod23">DataverseSpecification</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>"dataverse" <A HREF="#prod18">Identifier</A> <A HREF="#prod28">IfNotExists</A> ( "with format" <A HREF="#prod40">StringLiteral</A> )?</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod24">FunctionSpecification</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>"function" <A HREF="#prod41">FunctionName</A> <A HREF="#prod28">IfNotExists</A> <A HREF="#prod42">ParameterList</A> &lt;LEFTBRACE&gt; <A HREF="#prod43">Expression</A> &lt;RIGHTBRACE&gt;</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod25">FeedSpecification</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>( "secondary" "feed" <A HREF="#prod30">QualifiedName</A> <A HREF="#prod28">IfNotExists</A> &lt;FROM&gt; "feed" <A HREF="#prod30">QualifiedName</A> ( <A HREF="#prod44">ApplyFunction</A> )? | ( "primary" )? "feed" <A HREF="#prod30">QualifiedName</A> <A HREF="#prod28">IfNotExists</A> "using" <A HREF="#prod31">AdapterName</A> <A HREF="#prod32">Configuration</A> ( <A HREF="#prod44">ApplyFunction</A> )? )</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod26">FeedPolicySpecification</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>( "ingestion" "policy" <A HREF="#prod18">Identifier</A> <A HREF="#prod28">IfNotExists</A> &lt;FROM&gt; ( "policy" <A HREF="#prod18">Identifier</A> <A HREF="#prod32">Configuration</A> ( "definition" <A HREF="#prod40">StringLiteral</A> )? | "path" <A HREF="#prod18">Identifier</A> ( "definition" <A HREF="#prod40">StringLiteral</A> )? ) )</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod42">ParameterList</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>&lt;LEFTPAREN&gt; ( &lt;VARIABLE&gt; ( &lt;COMMA&gt; &lt;VARIABLE&gt; )* )? &lt;RIGHTPAREN&gt;</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod28">IfNotExists</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>( "if not exists" )?</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod44">ApplyFunction</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>"apply" "function" <A HREF="#prod41">FunctionName</A></TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod45">GetPolicy</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>"using" "policy" <A HREF="#prod18">Identifier</A></TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod46">FunctionSignature</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE><A HREF="#prod41">FunctionName</A> "@" &lt;INTEGER_LITERAL&gt;</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod35">PrimaryKey</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>"primary" "key" <A HREF="#prod36">NestedField</A> ( &lt;COMMA&gt; <A HREF="#prod36">NestedField</A> )*</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod7">DropStatement</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>"drop" ( &lt;DATASET&gt; <A HREF="#prod30">QualifiedName</A> <A HREF="#prod47">IfExists</A> | "index" <A HREF="#prod48">DoubleQualifiedName</A> <A HREF="#prod47">IfExists</A> | "nodegroup" <A HREF="#prod18">Identifier</A> <A HREF="#prod47">IfExists</A> | "type" <A HREF="#prod27">TypeName</A> <A HREF="#prod47">IfExists</A> | "dataverse" <A HREF="#prod18">Identifier</A> <A HREF="#prod47">IfExists</A> | "function" <A HREF="#prod46">FunctionSignature</A> <A HREF="#prod47">IfExists</A> | "feed" <A HREF="#prod30">QualifiedName</A> <A HREF="#prod47">IfExists</A> )</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod47">IfExists</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>( &lt;IF&gt; "exists" )?</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod10">InsertStatement</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>"insert" "into" &lt;DATASET&gt; <A HREF="#prod30">QualifiedName</A> <A HREF="#prod15">Query</A></TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod11">DeleteStatement</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>"delete" <A HREF="#prod49">Variable</A> &lt;FROM&gt; &lt;DATASET&gt; <A HREF="#prod30">QualifiedName</A> ( &lt;WHERE&gt; <A HREF="#prod43">Expression</A> )?</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod12">UpdateStatement</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>"update" <A HREF="#prod49">Variable</A> &lt;IN&gt; <A HREF="#prod43">Expression</A> &lt;WHERE&gt; <A HREF="#prod43">Expression</A> &lt;LEFTPAREN&gt; ( <A HREF="#prod50">UpdateClause</A> ( &lt;COMMA&gt; <A HREF="#prod50">UpdateClause</A> )* ) &lt;RIGHTPAREN&gt;</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod50">UpdateClause</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>( "set" <A HREF="#prod43">Expression</A> &lt;ASSIGN&gt; <A HREF="#prod43">Expression</A> | <A HREF="#prod10">InsertStatement</A> | <A HREF="#prod11">DeleteStatement</A> | <A HREF="#prod12">UpdateStatement</A> | &lt;IF&gt; &lt;LEFTPAREN&gt; <A HREF="#prod43">Expression</A> &lt;RIGHTPAREN&gt; &lt;THEN&gt; <A HREF="#prod50">UpdateClause</A> ( &lt;ELSE&gt; <A HREF="#prod50">UpdateClause</A> )? )</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod9">SetStatement</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>"set" <A HREF="#prod18">Identifier</A> <A HREF="#prod40">StringLiteral</A></TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod8">WriteStatement</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>"write" "output" "to" <A HREF="#prod18">Identifier</A> &lt;COLON&gt; <A HREF="#prod40">StringLiteral</A> ( "using" <A HREF="#prod40">StringLiteral</A> )?</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod6">LoadStatement</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>"load" &lt;DATASET&gt; <A HREF="#prod30">QualifiedName</A> "using" <A HREF="#prod31">AdapterName</A> <A HREF="#prod32">Configuration</A> ( "pre-sorted" )?</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod31">AdapterName</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE><A HREF="#prod18">Identifier</A></TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod14">CompactStatement</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>"compact" &lt;DATASET&gt; <A HREF="#prod30">QualifiedName</A></TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod13">FeedStatement</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>( "connect" "feed" <A HREF="#prod30">QualifiedName</A> "to" &lt;DATASET&gt; <A HREF="#prod30">QualifiedName</A> ( <A HREF="#prod45">GetPolicy</A> )? | "disconnect" "feed" <A HREF="#prod30">QualifiedName</A> &lt;FROM&gt; &lt;DATASET&gt; <A HREF="#prod30">QualifiedName</A> )</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod32">Configuration</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>&lt;LEFTPAREN&gt; ( <A HREF="#prod51">KeyValuePair</A> ( &lt;COMMA&gt; <A HREF="#prod51">KeyValuePair</A> )* )? &lt;RIGHTPAREN&gt;</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod51">KeyValuePair</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>&lt;LEFTPAREN&gt; <A HREF="#prod40">StringLiteral</A> &lt;EQ&gt; <A HREF="#prod40">StringLiteral</A> &lt;RIGHTPAREN&gt;</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod33">Properties</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>( &lt;LEFTPAREN&gt; <A HREF="#prod52">Property</A> ( &lt;COMMA&gt; <A HREF="#prod52">Property</A> )* &lt;RIGHTPAREN&gt; )?</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod52">Property</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE><A HREF="#prod18">Identifier</A> &lt;EQ&gt; ( <A HREF="#prod40">StringLiteral</A> | &lt;INTEGER_LITERAL&gt; )</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod53">IndexedTypeExpr</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>( <A HREF="#prod54">TypeReference</A> | <A HREF="#prod55">OrderedListTypeDef</A> | <A HREF="#prod56">UnorderedListTypeDef</A> )</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod29">TypeExpr</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>( <A HREF="#prod57">RecordTypeDef</A> | <A HREF="#prod54">TypeReference</A> | <A HREF="#prod55">OrderedListTypeDef</A> | <A HREF="#prod56">UnorderedListTypeDef</A> )</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod57">RecordTypeDef</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>( "closed" | "open" )? &lt;LEFTBRACE&gt; ( <A HREF="#prod58">RecordField</A> ( &lt;COMMA&gt; <A HREF="#prod58">RecordField</A> )* )? &lt;RIGHTBRACE&gt;</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod58">RecordField</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE><A HREF="#prod18">Identifier</A> &lt;COLON&gt; <A HREF="#prod29">TypeExpr</A> ( &lt;QUES&gt; )?</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod54">TypeReference</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE><A HREF="#prod18">Identifier</A></TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod55">OrderedListTypeDef</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>&lt;LEFTBRACKET&gt; ( <A HREF="#prod29">TypeExpr</A> ) &lt;RIGHTBRACKET&gt;</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod56">UnorderedListTypeDef</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>&lt;LEFTDBLBRACE&gt; ( <A HREF="#prod29">TypeExpr</A> ) &lt;RIGHTDBLBRACE&gt;</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod41">FunctionName</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE><A HREF="#prod18">Identifier</A> ( &lt;DOT&gt; <A HREF="#prod18">Identifier</A> ( "#" <A HREF="#prod18">Identifier</A> )? | "#" <A HREF="#prod18">Identifier</A> )?</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod27">TypeName</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE><A HREF="#prod30">QualifiedName</A></TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod18">Identifier</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>( &lt;IDENTIFIER&gt; | <A HREF="#prod40">StringLiteral</A> )</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod37">OpenField</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE><A HREF="#prod36">NestedField</A> ( &lt;COLON&gt; <A HREF="#prod53">IndexedTypeExpr</A> )?</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod36">NestedField</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE><A HREF="#prod18">Identifier</A> ( &lt;DOT&gt; <A HREF="#prod18">Identifier</A> )*</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod40">StringLiteral</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>&lt;STRING_LITERAL&gt;</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod30">QualifiedName</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE><A HREF="#prod18">Identifier</A> ( &lt;DOT&gt; <A HREF="#prod18">Identifier</A> )?</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod48">DoubleQualifiedName</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE><A HREF="#prod18">Identifier</A> &lt;DOT&gt; <A HREF="#prod18">Identifier</A> ( &lt;DOT&gt; <A HREF="#prod18">Identifier</A> )?</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod4">FunctionDeclaration</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>"declare" "function" <A HREF="#prod18">Identifier</A> <A HREF="#prod42">ParameterList</A> &lt;LEFTBRACE&gt; <A HREF="#prod43">Expression</A> &lt;RIGHTBRACE&gt;</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod15">Query</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE><A HREF="#prod43">Expression</A></TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod43">Expression</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>( <A HREF="#prod59">OperatorExpr</A> | <A HREF="#prod60">IfThenElse</A> | <A HREF="#prod61">FLWOGR</A> | <A HREF="#prod62">QuantifiedExpression</A> )</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod59">OperatorExpr</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE><A HREF="#prod63">AndExpr</A> ( &lt;OR&gt; <A HREF="#prod63">AndExpr</A> )*</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod63">AndExpr</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE><A HREF="#prod64">RelExpr</A> ( &lt;AND&gt; <A HREF="#prod64">RelExpr</A> )*</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod64">RelExpr</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE><A HREF="#prod65">AddExpr</A> ( ( &lt;LT&gt; | &lt;GT&gt; | &lt;LE&gt; | &lt;GE&gt; | &lt;EQ&gt; | &lt;NE&gt; | &lt;SIMILAR&gt; ) <A HREF="#prod65">AddExpr</A> )?</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod65">AddExpr</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE><A HREF="#prod66">MultExpr</A> ( ( &lt;PLUS&gt; | &lt;MINUS&gt; ) <A HREF="#prod66">MultExpr</A> )*</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod66">MultExpr</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE><A HREF="#prod67">UnionExpr</A> ( ( &lt;MUL&gt; | &lt;DIV&gt; | &lt;MOD&gt; | &lt;CARET&gt; | &lt;IDIV&gt; ) <A HREF="#prod67">UnionExpr</A> )*</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod67">UnionExpr</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE><A HREF="#prod68">UnaryExpr</A> ( &lt;UNION&gt; ( <A HREF="#prod68">UnaryExpr</A> ) )*</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod68">UnaryExpr</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>( ( &lt;PLUS&gt; | &lt;MINUS&gt; ) )? <A HREF="#prod69">ValueExpr</A></TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod69">ValueExpr</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE><A HREF="#prod70">PrimaryExpr</A> ( <A HREF="#prod71">Field</A> | <A HREF="#prod72">Index</A> )*</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod71">Field</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>&lt;DOT&gt; <A HREF="#prod18">Identifier</A></TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod72">Index</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>&lt;LEFTBRACKET&gt; ( <A HREF="#prod43">Expression</A> | &lt;QUES&gt; ) &lt;RIGHTBRACKET&gt;</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod70">PrimaryExpr</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>( <A HREF="#prod73">FunctionCallExpr</A> | <A HREF="#prod74">Literal</A> | <A HREF="#prod75">DatasetAccessExpression</A> | <A HREF="#prod76">VariableRef</A> | <A HREF="#prod77">ListConstructor</A> | <A HREF="#prod78">RecordConstructor</A> | <A HREF="#prod79">ParenthesizedExpression</A> )</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod74">Literal</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>( <A HREF="#prod40">StringLiteral</A> | &lt;INTEGER_LITERAL&gt; | &lt;FLOAT_LITERAL&gt; | &lt;DOUBLE_LITERAL&gt; | &lt;NULL&gt; | &lt;TRUE&gt; | &lt;FALSE&gt; )</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod76">VariableRef</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>&lt;VARIABLE&gt;</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod49">Variable</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>&lt;VARIABLE&gt;</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod77">ListConstructor</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>( <A HREF="#prod80">OrderedListConstructor</A> | <A HREF="#prod81">UnorderedListConstructor</A> )</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod80">OrderedListConstructor</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>&lt;LEFTBRACKET&gt; <A HREF="#prod82">ExpressionList</A> &lt;RIGHTBRACKET&gt;</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod81">UnorderedListConstructor</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>&lt;LEFTDBLBRACE&gt; <A HREF="#prod82">ExpressionList</A> &lt;RIGHTDBLBRACE&gt;</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod82">ExpressionList</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>( <A HREF="#prod43">Expression</A> ( &lt;COMMA&gt; <A HREF="#prod82">ExpressionList</A> )? )? ( <A HREF="#prod83">Comma</A> )?</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod83">Comma</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>&lt;COMMA&gt;</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod78">RecordConstructor</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>&lt;LEFTBRACE&gt; ( <A HREF="#prod84">FieldBinding</A> ( &lt;COMMA&gt; <A HREF="#prod84">FieldBinding</A> )* )? &lt;RIGHTBRACE&gt;</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod84">FieldBinding</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE><A HREF="#prod43">Expression</A> &lt;COLON&gt; <A HREF="#prod43">Expression</A></TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod73">FunctionCallExpr</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE><A HREF="#prod41">FunctionName</A> &lt;LEFTPAREN&gt; ( <A HREF="#prod43">Expression</A> ( &lt;COMMA&gt; <A HREF="#prod43">Expression</A> )* )? &lt;RIGHTPAREN&gt;</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod75">DatasetAccessExpression</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>&lt;DATASET&gt; ( ( <A HREF="#prod18">Identifier</A> ( &lt;DOT&gt; <A HREF="#prod18">Identifier</A> )? ) | ( &lt;LEFTPAREN&gt; <A HREF="#prod43">Expression</A> &lt;RIGHTPAREN&gt; ) )</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod79">ParenthesizedExpression</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>&lt;LEFTPAREN&gt; <A HREF="#prod43">Expression</A> &lt;RIGHTPAREN&gt;</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod60">IfThenElse</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>&lt;IF&gt; &lt;LEFTPAREN&gt; <A HREF="#prod43">Expression</A> &lt;RIGHTPAREN&gt; &lt;THEN&gt; <A HREF="#prod43">Expression</A> &lt;ELSE&gt; <A HREF="#prod43">Expression</A></TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod61">FLWOGR</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>( <A HREF="#prod85">ForClause</A> | <A HREF="#prod86">LetClause</A> ) ( <A HREF="#prod87">Clause</A> )* ( &lt;RETURN&gt; | &lt;SELECT&gt; ) <A HREF="#prod43">Expression</A></TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod87">Clause</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>( <A HREF="#prod85">ForClause</A> | <A HREF="#prod86">LetClause</A> | <A HREF="#prod88">WhereClause</A> | <A HREF="#prod89">OrderbyClause</A> | <A HREF="#prod90">GroupClause</A> | <A HREF="#prod91">LimitClause</A> | <A HREF="#prod92">DistinctClause</A> )</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod85">ForClause</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>( &lt;FOR&gt; | &lt;FROM&gt; ) <A HREF="#prod49">Variable</A> ( &lt;AT&gt; <A HREF="#prod49">Variable</A> )? &lt;IN&gt; ( <A HREF="#prod43">Expression</A> )</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod86">LetClause</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>( &lt;LET&gt; | &lt;WITH&gt; ) <A HREF="#prod49">Variable</A> &lt;ASSIGN&gt; <A HREF="#prod43">Expression</A></TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod88">WhereClause</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>&lt;WHERE&gt; <A HREF="#prod43">Expression</A></TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod89">OrderbyClause</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>( &lt;ORDER&gt; &lt;BY&gt; <A HREF="#prod43">Expression</A> ( ( &lt;ASC&gt; ) | ( &lt;DESC&gt; ) )? ( &lt;COMMA&gt; <A HREF="#prod43">Expression</A> ( ( &lt;ASC&gt; ) | ( &lt;DESC&gt; ) )? )* )</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod90">GroupClause</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>&lt;GROUP&gt; &lt;BY&gt; ( <A HREF="#prod49">Variable</A> &lt;ASSIGN&gt; )? <A HREF="#prod43">Expression</A> ( &lt;COMMA&gt; ( <A HREF="#prod49">Variable</A> &lt;ASSIGN&gt; )? <A HREF="#prod43">Expression</A> )* ( &lt;DECOR&gt; <A HREF="#prod49">Variable</A> &lt;ASSIGN&gt; <A HREF="#prod43">Expression</A> ( &lt;COMMA&gt; &lt;DECOR&gt; <A HREF="#prod49">Variable</A> &lt;ASSIGN&gt; <A HREF="#prod43">Expression</A> )* )? ( &lt;WITH&gt; | &lt;KEEPING&gt; ) <A HREF="#prod76">VariableRef</A> ( &lt;COMMA&gt; <A HREF="#prod76">VariableRef</A> )*</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod91">LimitClause</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>&lt;LIMIT&gt; <A HREF="#prod43">Expression</A> ( &lt;OFFSET&gt; <A HREF="#prod43">Expression</A> )?</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod92">DistinctClause</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>&lt;DISTINCT&gt; &lt;BY&gt; <A HREF="#prod43">Expression</A> ( &lt;COMMA&gt; <A HREF="#prod43">Expression</A> )*</TD>
+</TR>
+<TR>
+<TD ALIGN=RIGHT VALIGN=BASELINE><A NAME="prod62">QuantifiedExpression</A></TD>
+<TD ALIGN=CENTER VALIGN=BASELINE>::=</TD>
+<TD ALIGN=LEFT VALIGN=BASELINE>( ( &lt;SOME&gt; ) | ( &lt;EVERY&gt; ) ) <A HREF="#prod49">Variable</A> &lt;IN&gt; <A HREF="#prod43">Expression</A> ( &lt;COMMA&gt; <A HREF="#prod49">Variable</A> &lt;IN&gt; <A HREF="#prod43">Expression</A> )* &lt;SATISFIES&gt; <A HREF="#prod43">Expression</A></TD>
+</TR>
+</TABLE>
+</BODY>
+</HTML>
diff --git a/asterix-lang-aql/src/main/javacc/AQL.jj b/asterix-lang-aql/src/main/javacc/AQL.jj
new file mode 100644
index 0000000..bb574d0
--- /dev/null
+++ b/asterix-lang-aql/src/main/javacc/AQL.jj
@@ -0,0 +1,2684 @@
+options {
+
+
+       STATIC = false;
+
+}
+
+
+PARSER_BEGIN(AQLParser)
+
+package org.apache.asterix.lang.aql.parser;
+
+// For AQLParserTokenManager
+import org.apache.xerces.util.IntStack;
+
+import java.io.BufferedReader;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.io.Reader;
+import java.io.StringReader;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+
+import org.apache.asterix.common.annotations.AutoDataGen;
+import org.apache.asterix.common.annotations.DateBetweenYearsDataGen;
+import org.apache.asterix.common.annotations.DatetimeAddRandHoursDataGen;
+import org.apache.asterix.common.annotations.DatetimeBetweenYearsDataGen;
+import org.apache.asterix.common.annotations.FieldIntervalDataGen;
+import org.apache.asterix.common.annotations.FieldValFileDataGen;
+import org.apache.asterix.common.annotations.FieldValFileSameIndexDataGen;
+import org.apache.asterix.common.annotations.IRecordFieldDataGen;
+import org.apache.asterix.common.annotations.InsertRandIntDataGen;
+import org.apache.asterix.common.annotations.ListDataGen;
+import org.apache.asterix.common.annotations.ListValFileDataGen;
+import org.apache.asterix.common.annotations.SkipSecondaryIndexSearchExpressionAnnotation;
+import org.apache.asterix.common.annotations.TypeDataGen;
+import org.apache.asterix.common.annotations.UndeclaredFieldsDataGen;
+import org.apache.asterix.common.config.DatasetConfig.DatasetType;
+import org.apache.asterix.common.config.DatasetConfig.IndexType;
+import org.apache.asterix.common.exceptions.AsterixException;
+import org.apache.asterix.common.functions.FunctionSignature;
+import org.apache.asterix.lang.aql.clause.DistinctClause;
+import org.apache.asterix.lang.aql.clause.ForClause;
+import org.apache.asterix.lang.aql.expression.FLWOGRExpression;
+import org.apache.asterix.lang.aql.expression.UnionExpr;
+import org.apache.asterix.lang.aql.util.RangeMapBuilder;
+import org.apache.asterix.lang.common.base.Clause;
+import org.apache.asterix.lang.common.base.Expression;
+import org.apache.asterix.lang.common.base.IParser;
+import org.apache.asterix.lang.common.base.Literal;
+import org.apache.asterix.lang.common.base.Statement;
+import org.apache.asterix.lang.common.clause.GroupbyClause;
+import org.apache.asterix.lang.common.clause.LetClause;
+import org.apache.asterix.lang.common.clause.LimitClause;
+import org.apache.asterix.lang.common.clause.OrderbyClause;
+import org.apache.asterix.lang.common.clause.UpdateClause;
+import org.apache.asterix.lang.common.clause.WhereClause;
+import org.apache.asterix.lang.common.context.RootScopeFactory;
+import org.apache.asterix.lang.common.context.Scope;
+import org.apache.asterix.lang.common.expression.AbstractAccessor;
+import org.apache.asterix.lang.common.expression.CallExpr;
+import org.apache.asterix.lang.common.expression.FieldAccessor;
+import org.apache.asterix.lang.common.expression.FieldBinding;
+import org.apache.asterix.lang.common.expression.GbyVariableExpressionPair;
+import org.apache.asterix.lang.common.expression.IfExpr;
+import org.apache.asterix.lang.common.expression.IndexAccessor;
+import org.apache.asterix.lang.common.expression.ListConstructor;
+import org.apache.asterix.lang.common.expression.LiteralExpr;
+import org.apache.asterix.lang.common.expression.OperatorExpr;
+import org.apache.asterix.lang.common.expression.OrderedListTypeDefinition;
+import org.apache.asterix.lang.common.expression.QuantifiedExpression;
+import org.apache.asterix.lang.common.expression.RecordConstructor;
+import org.apache.asterix.lang.common.expression.RecordTypeDefinition;
+import org.apache.asterix.lang.common.expression.TypeExpression;
+import org.apache.asterix.lang.common.expression.TypeReferenceExpression;
+import org.apache.asterix.lang.common.expression.UnaryExpr;
+import org.apache.asterix.lang.common.expression.UnorderedListTypeDefinition;
+import org.apache.asterix.lang.common.expression.VariableExpr;
+import org.apache.asterix.lang.common.expression.UnaryExpr.Sign;
+import org.apache.asterix.lang.common.literal.DoubleLiteral;
+import org.apache.asterix.lang.common.literal.FalseLiteral;
+import org.apache.asterix.lang.common.literal.FloatLiteral;
+import org.apache.asterix.lang.common.literal.LongIntegerLiteral;
+import org.apache.asterix.lang.common.literal.NullLiteral;
+import org.apache.asterix.lang.common.literal.StringLiteral;
+import org.apache.asterix.lang.common.literal.TrueLiteral;
+import org.apache.asterix.lang.common.parser.ScopeChecker;
+import org.apache.asterix.lang.common.statement.CompactStatement;
+import org.apache.asterix.lang.common.statement.ConnectFeedStatement;
+import org.apache.asterix.lang.common.statement.CreateDataverseStatement;
+import org.apache.asterix.lang.common.statement.CreateFeedPolicyStatement;
+import org.apache.asterix.lang.common.statement.CreateFeedStatement;
+import org.apache.asterix.lang.common.statement.CreateFunctionStatement;
+import org.apache.asterix.lang.common.statement.CreateIndexStatement;
+import org.apache.asterix.lang.common.statement.CreatePrimaryFeedStatement;
+import org.apache.asterix.lang.common.statement.CreateSecondaryFeedStatement;
+import org.apache.asterix.lang.common.statement.DatasetDecl;
+import org.apache.asterix.lang.common.statement.DataverseDecl;
+import org.apache.asterix.lang.common.statement.DataverseDropStatement;
+import org.apache.asterix.lang.common.statement.DeleteStatement;
+import org.apache.asterix.lang.common.statement.DisconnectFeedStatement;
+import org.apache.asterix.lang.common.statement.DropStatement;
+import org.apache.asterix.lang.common.statement.ExternalDetailsDecl;
+import org.apache.asterix.lang.common.statement.FeedDropStatement;
+import org.apache.asterix.lang.common.statement.FunctionDecl;
+import org.apache.asterix.lang.common.statement.FunctionDropStatement;
+import org.apache.asterix.lang.common.statement.IndexDropStatement;
+import org.apache.asterix.lang.common.statement.InsertStatement;
+import org.apache.asterix.lang.common.statement.InternalDetailsDecl;
+import org.apache.asterix.lang.common.statement.LoadStatement;
+import org.apache.asterix.lang.common.statement.NodeGroupDropStatement;
+import org.apache.asterix.lang.common.statement.NodegroupDecl;
+import org.apache.asterix.lang.common.statement.Query;
+import org.apache.asterix.lang.common.statement.RefreshExternalDatasetStatement;
+import org.apache.asterix.lang.common.statement.RunStatement;
+import org.apache.asterix.lang.common.statement.SetStatement;
+import org.apache.asterix.lang.common.statement.TypeDecl;
+import org.apache.asterix.lang.common.statement.TypeDropStatement;
+import org.apache.asterix.lang.common.statement.UpdateStatement;
+import org.apache.asterix.lang.common.statement.WriteStatement;
+import org.apache.asterix.lang.common.struct.Identifier;
+import org.apache.asterix.lang.common.struct.QuantifiedPair;
+import org.apache.asterix.lang.common.struct.VarIdentifier;
+import org.apache.asterix.metadata.bootstrap.MetadataConstants;
+import org.apache.hyracks.algebricks.common.utils.Pair;
+import org.apache.hyracks.algebricks.common.utils.Triple;
+import org.apache.hyracks.algebricks.core.algebra.expressions.IExpressionAnnotation;
+import org.apache.hyracks.algebricks.core.algebra.expressions.IndexedNLJoinExpressionAnnotation;
+import org.apache.hyracks.algebricks.core.algebra.functions.FunctionIdentifier;
+
+
+public class AQLParser extends ScopeChecker implements IParser {
+
+    // optimizer hints
+    private static final String AUTO_HINT = "auto";
+    private static final String BROADCAST_JOIN_HINT = "bcast";
+    private static final String COMPOSE_VAL_FILES_HINT = "compose-val-files";
+    private static final String DATE_BETWEEN_YEARS_HINT = "date-between-years";
+    private static final String DATETIME_ADD_RAND_HOURS_HINT = "datetime-add-rand-hours";
+    private static final String DATETIME_BETWEEN_YEARS_HINT = "datetime-between-years";
+    private static final String HASH_GROUP_BY_HINT = "hash";
+    private static final String INDEXED_NESTED_LOOP_JOIN_HINT = "indexnl";
+    private static final String INMEMORY_HINT = "inmem";
+    private static final String INSERT_RAND_INT_HINT = "insert-rand-int";
+    private static final String INTERVAL_HINT = "interval";
+    private static final String LIST_HINT = "list";
+    private static final String LIST_VAL_FILE_HINT = "list-val-file";
+    private static final String RANGE_HINT = "range";
+    private static final String SKIP_SECONDARY_INDEX_SEARCH_HINT = "skip-index";
+    private static final String VAL_FILE_HINT = "val-files";
+    private static final String VAL_FILE_SAME_INDEX_HINT = "val-file-same-idx";
+
+    private static final String GEN_FIELDS_HINT = "gen-fields";
+
+    // data generator hints
+    private static final String DGEN_HINT = "dgen";
+
+    private static class IndexParams {
+      public IndexType type;
+      public int gramLength;
+
+      public IndexParams(IndexType type, int gramLength) {
+        this.type = type;
+        this.gramLength = gramLength;
+      }
+    };
+
+    private static class FunctionName {
+       public String dataverse = null;
+       public String library = null;
+       public String function = null;
+       public String hint = null;
+    }
+
+    private static String getHint(Token t) {
+        if (t.specialToken == null) {
+            return null;
+        }
+        String s = t.specialToken.image;
+        int n = s.length();
+        if (n < 2) {
+            return null;
+        }
+        return s.substring(1).trim();
+    }
+
+    private static IRecordFieldDataGen parseFieldDataGen(String hint) throws ParseException {
+      IRecordFieldDataGen rfdg = null;
+      String splits[] = hint.split(" +");
+      if (splits[0].equals(VAL_FILE_HINT)) {
+        File[] valFiles = new File[splits.length - 1];
+        for (int k=1; k<splits.length; k++) {
+          valFiles[k-1] = new File(splits[k]);
+        }
+        rfdg = new FieldValFileDataGen(valFiles);
+      } else if (splits[0].equals(VAL_FILE_SAME_INDEX_HINT)) {
+        rfdg = new FieldValFileSameIndexDataGen(new File(splits[1]), splits[2]);
+      } else if (splits[0].equals(LIST_VAL_FILE_HINT)) {
+        rfdg = new ListValFileDataGen(new File(splits[1]), Integer.parseInt(splits[2]), Integer.parseInt(splits[3]));
+      } else if (splits[0].equals(LIST_HINT)) {
+        rfdg = new ListDataGen(Integer.parseInt(splits[1]), Integer.parseInt(splits[2]));
+      } else if (splits[0].equals(INTERVAL_HINT)) {
+        FieldIntervalDataGen.ValueType vt;
+        if (splits[1].equals("int")) {
+          vt = FieldIntervalDataGen.ValueType.INT;
+        } else if (splits[1].equals("long")) {
+          vt = FieldIntervalDataGen.ValueType.LONG;
+        } else if (splits[1].equals("float")) {
+          vt = FieldIntervalDataGen.ValueType.FLOAT;
+        } else if (splits[1].equals("double")) {
+          vt = FieldIntervalDataGen.ValueType.DOUBLE;
+        } else {
+          throw new ParseException("Unknown type for interval data gen: " + splits[1]);
+        }
+        rfdg = new FieldIntervalDataGen(vt, splits[2], splits[3]);
+      } else if (splits[0].equals(INSERT_RAND_INT_HINT)) {
+        rfdg = new InsertRandIntDataGen(splits[1], splits[2]);
+      } else if (splits[0].equals(DATE_BETWEEN_YEARS_HINT)) {
+        rfdg = new DateBetweenYearsDataGen(Integer.parseInt(splits[1]), Integer.parseInt(splits[2]));
+      } else if (splits[0].equals(DATETIME_BETWEEN_YEARS_HINT)) {
+        rfdg = new DatetimeBetweenYearsDataGen(Integer.parseInt(splits[1]), Integer.parseInt(splits[2]));
+      } else if (splits[0].equals(DATETIME_ADD_RAND_HOURS_HINT)) {
+        rfdg = new DatetimeAddRandHoursDataGen(Integer.parseInt(splits[1]), Integer.parseInt(splits[2]), splits[3]);
+      } else if (splits[0].equals(AUTO_HINT)) {
+        rfdg = new AutoDataGen(splits[1]);
+      }
+      return rfdg;
+    }
+
+    public AQLParser(String s){
+        this(new StringReader(s));
+        super.setInput(s);
+    }
+
+    public static void main(String args[]) throws ParseException, TokenMgrError, IOException, FileNotFoundException, AsterixException {
+        File file = new File(args[0]);
+        Reader fis = new BufferedReader(new InputStreamReader(new FileInputStream(file), "UTF-8"));
+        AQLParser parser = new AQLParser(fis);
+        List<Statement> st = parser.parse();
+        //st.accept(new AQLPrintVisitor(), 0);
+    }
+
+    public List<Statement> parse() throws AsterixException {
+        try {
+            return Statement();
+        } catch (Error e) {
+            // this is here as the JavaCharStream that's below the lexer somtimes throws Errors that are not handled
+            // by the ANTLR-generated lexer or parser (e.g it does this for invalid backslash u + 4 hex digits escapes)
+            throw new AsterixException(new ParseException(e.getMessage()));
+        } catch (ParseException e){
+            throw new AsterixException(e.getMessage());
+        }
+    }
+}
+
+PARSER_END(AQLParser)
+
+
+List<Statement> Statement() throws ParseException:
+{
+  scopeStack.push(RootScopeFactory.createRootScope(this));
+  List<Statement> decls = new ArrayList<Statement>();
+  Statement stmt = null;
+}
+{
+  ( stmt = SingleStatement() (";") ?
+    {
+      decls.add(stmt);
+    }
+  )*
+  <EOF>
+  {
+    return decls;
+  }
+}
+
+Statement SingleStatement() throws ParseException:
+{
+  Statement stmt = null;
+}
+{
+  (
+    stmt = DataverseDeclaration()
+    | stmt = FunctionDeclaration()
+    | stmt = CreateStatement()
+    | stmt = LoadStatement()
+    | stmt = DropStatement()
+    | stmt = WriteStatement()
+    | stmt = SetStatement()
+    | stmt = InsertStatement()
+    | stmt = DeleteStatement()
+    | stmt = UpdateStatement()
+    | stmt = FeedStatement()
+    | stmt = CompactStatement()
+    | stmt = Query()
+    | stmt = RefreshExternalDatasetStatement()
+    | stmt = RunStatement()
+  )
+  {
+    return stmt;
+  }
+}
+
+DataverseDecl DataverseDeclaration() throws ParseException:
+{
+  String dvName = null;
+}
+{
+  "use" "dataverse" dvName = Identifier()
+    {
+      defaultDataverse = dvName;
+      return new DataverseDecl(new Identifier(dvName));
+    }
+}
+
+Statement CreateStatement() throws ParseException:
+{
+  String hint = null;
+  boolean dgen = false;
+  Statement stmt = null;
+}
+{
+  "create"
+  (
+    {
+      hint = getHint(token);
+      if (hint != null && hint.startsWith(DGEN_HINT)) {
+        dgen = true;
+      }
+    }
+    stmt = TypeSpecification(hint, dgen)
+    | stmt = NodegroupSpecification()
+    | stmt = DatasetSpecification()
+    | stmt = IndexSpecification()
+    | stmt = DataverseSpecification()
+    | stmt = FunctionSpecification()
+    | stmt = FeedSpecification()
+    | stmt = FeedPolicySpecification()
+  )
+  {
+    return stmt;
+  }
+}
+
+TypeDecl TypeSpecification(String hint, boolean dgen) throws ParseException:
+{
+  Pair<Identifier,Identifier> nameComponents = null;
+  boolean ifNotExists = false;
+  TypeExpression typeExpr = null;
+}
+{
+  "type" nameComponents = TypeName() ifNotExists = IfNotExists()
+  "as" typeExpr = TypeExpr()
+    {
+      long numValues = -1;
+      String filename = null;
+      if (dgen) {
+        String splits[] = hint.split(" +");
+        if (splits.length != 3) {
+          throw new ParseException("Expecting /*+ dgen <filename> <numberOfItems> */");
+        }
+        filename = splits[1];
+        numValues = Long.parseLong(splits[2]);
+      }
+      TypeDataGen tddg = new TypeDataGen(dgen, filename, numValues);
+      return new TypeDecl(nameComponents.first, nameComponents.second, typeExpr, tddg, ifNotExists);
+    }
+}
+
+
+NodegroupDecl NodegroupSpecification() throws ParseException:
+{
+  String name = null;
+  String tmp = null;
+  boolean ifNotExists = false;
+  List<Identifier>ncNames = null;
+}
+{
+  "nodegroup" name = Identifier()
+  ifNotExists = IfNotExists() "on" tmp = Identifier()
+    {
+      ncNames = new ArrayList<Identifier>();
+      ncNames.add(new Identifier(tmp));
+    }
+  ( <COMMA> tmp = Identifier()
+    {
+      ncNames.add(new Identifier(tmp));
+    }
+  )*
+    {
+      return new NodegroupDecl(new Identifier(name), ncNames, ifNotExists);
+    }
+}
+
+DatasetDecl DatasetSpecification() throws ParseException:
+{
+  Pair<Identifier,Identifier> nameComponents = null;
+  boolean ifNotExists = false;
+  String typeName = null;
+  String adapterName = null;
+  Map<String,String> properties = null;
+  Map<String,String> compactionPolicyProperties = null;
+  FunctionSignature appliedFunction = null;
+  List<List<String>> primaryKeyFields = null;
+  String nodeGroupName = null;
+  Map<String,String> hints = new HashMap<String,String>();
+  DatasetDecl dsetDecl = null;
+  boolean autogenerated = false;
+  String compactionPolicy = null;
+  boolean temp = false;
+  List<String> filterField = null;
+}
+{
+  (
+    "external" <DATASET> nameComponents = QualifiedName()
+    <LEFTPAREN> typeName = Identifier() <RIGHTPAREN>
+    ifNotExists = IfNotExists()
+    "using" adapterName = AdapterName() properties = Configuration()
+    ("on" nodeGroupName = Identifier() )?
+    ( "hints" hints = Properties() )?
+    ( "using" "compaction" "policy" compactionPolicy = CompactionPolicy() (compactionPolicyProperties = Configuration())? )?
+      {
+        ExternalDetailsDecl edd = new ExternalDetailsDecl();
+        edd.setAdapter(adapterName);
+        edd.setProperties(properties);
+        dsetDecl = new DatasetDecl(nameComponents.first,
+                                   nameComponents.second,
+                                   new Identifier(typeName),
+                                   nodeGroupName != null? new Identifier(nodeGroupName): null,
+                                   compactionPolicy,
+                                   compactionPolicyProperties,
+                                   hints,
+                                   DatasetType.EXTERNAL,
+                                   edd,
+                                   ifNotExists);
+      }
+
+    | ("internal" | "temporary" {
+            temp = token.image.toLowerCase().equals("temporary");
+        }
+      )? 
+    <DATASET> nameComponents = QualifiedName()
+    <LEFTPAREN> typeName = Identifier() <RIGHTPAREN>
+    ifNotExists = IfNotExists()
+    primaryKeyFields = PrimaryKey()
+    ("autogenerated" { autogenerated = true; } )?
+    ("on" nodeGroupName = Identifier() )?
+    ( "hints" hints = Properties() )?
+    ( "using" "compaction" "policy" compactionPolicy = CompactionPolicy() (compactionPolicyProperties = Configuration())? )?
+    ( "with filter on" filterField = NestedField() )?
+      {
+        InternalDetailsDecl idd = new InternalDetailsDecl(primaryKeyFields,
+                                                          autogenerated,
+                                                          filterField,
+                                                          temp);
+        dsetDecl = new DatasetDecl(nameComponents.first,
+                                   nameComponents.second,
+                                   new Identifier(typeName),
+                                   nodeGroupName != null ? new Identifier(nodeGroupName) : null,
+                                   compactionPolicy,
+                                   compactionPolicyProperties,
+                                   hints,
+                                   DatasetType.INTERNAL,
+                                   idd,
+                                   ifNotExists);
+      }
+  )
+    {
+      return dsetDecl;
+    }
+}
+
+RefreshExternalDatasetStatement RefreshExternalDatasetStatement() throws ParseException:
+{
+  RefreshExternalDatasetStatement redss = new RefreshExternalDatasetStatement();
+  Pair<Identifier,Identifier> nameComponents = null;
+  String datasetName = null;
+}
+{
+    "refresh external" <DATASET> nameComponents = QualifiedName()
+    {
+    redss.setDataverseName(nameComponents.first);
+    redss.setDatasetName(nameComponents.second);
+    return redss;
+    }
+}
+
+RunStatement RunStatement() throws ParseException:
+{
+  String system = null;
+  String tmp;
+  ArrayList<String> parameters = new  ArrayList<String>();
+  Pair<Identifier,Identifier> nameComponentsFrom = null;
+  Pair<Identifier,Identifier> nameComponentsTo = null;
+}
+{
+  "run" system = Identifier()<LEFTPAREN> ( tmp = Identifier() [<COMMA>]
+    {
+      parameters.add(tmp);
+    }
+  )*<RIGHTPAREN>
+  <FROM> <DATASET> nameComponentsFrom  = QualifiedName()
+  "to" <DATASET> nameComponentsTo  = QualifiedName()
+    {
+      return new RunStatement(system, parameters, nameComponentsFrom.first, nameComponentsFrom.second, nameComponentsTo.first, nameComponentsTo.second);
+    }
+}
+
+CreateIndexStatement IndexSpecification() throws ParseException:
+{
+  CreateIndexStatement cis = new CreateIndexStatement();
+  String indexName = null;
+  boolean ifNotExists = false;
+  Pair<Identifier,Identifier> nameComponents = null;
+  Pair<List<String>, TypeExpression> fieldPair = null;
+  IndexParams indexType = null;
+  boolean enforced = false;
+}
+{
+  "index" indexName = Identifier()
+  ifNotExists = IfNotExists()
+  "on" nameComponents = QualifiedName()
+  <LEFTPAREN> ( fieldPair = OpenField()
+    {
+      cis.addFieldExprPair(fieldPair);
+    }
+  ) (<COMMA> fieldPair = OpenField()
+    {
+      cis.addFieldExprPair(fieldPair);
+    }
+  )* <RIGHTPAREN> ( "type" indexType = IndexType() )? ( "enforced" { enforced = true; } )?
+    {
+      cis.setIndexName(new Identifier(indexName));
+      cis.setIfNotExists(ifNotExists);
+      cis.setDataverseName(nameComponents.first);
+      cis.setDatasetName(nameComponents.second);
+      if (indexType != null) {
+        cis.setIndexType(indexType.type);
+        cis.setGramLength(indexType.gramLength);
+      }
+      cis.setEnforced(enforced);
+      return cis;
+    }
+}
+
+String CompactionPolicy() throws ParseException :
+{
+  String compactionPolicy = null;
+}
+{
+  compactionPolicy = Identifier()
+    {
+      return compactionPolicy;
+    }
+}
+
+String FilterField() throws ParseException :
+{
+  String filterField = null;
+}
+{
+  filterField = Identifier()
+    {
+      return filterField;
+    }
+}
+
+IndexParams IndexType() throws ParseException:
+{
+  IndexType type = null;
+  int gramLength = 0;
+}
+{
+  ("btree"
+    {
+      type = IndexType.BTREE;
+    }
+  | "rtree"
+    {
+      type = IndexType.RTREE;
+    }
+  | "keyword"
+    {
+      type = IndexType.LENGTH_PARTITIONED_WORD_INVIX;
+    }
+  | "ngram" <LEFTPAREN> <INTEGER_LITERAL>
+    {
+      type = IndexType.LENGTH_PARTITIONED_NGRAM_INVIX;
+      gramLength = Integer.valueOf(token.image);
+    }
+  <RIGHTPAREN>)
+    {
+      return new IndexParams(type, gramLength);
+    }
+}
+
+CreateDataverseStatement DataverseSpecification() throws ParseException :
+{
+  String dvName = null;
+  boolean ifNotExists = false;
+  String format = null;
+}
+{
+  "dataverse" dvName = Identifier()
+  ifNotExists = IfNotExists()
+  ( "with format" format = StringLiteral() )?
+    {
+      return new CreateDataverseStatement(new Identifier(dvName), format, ifNotExists);
+    }
+}
+
+CreateFunctionStatement FunctionSpecification() throws ParseException:
+{
+  FunctionSignature signature;
+  boolean ifNotExists = false;
+  List<VarIdentifier> paramList = new ArrayList<VarIdentifier>();
+  String functionBody;
+  VarIdentifier var = null;
+  Expression functionBodyExpr;
+  Token beginPos;
+  Token endPos;
+  FunctionName fctName = null;
+
+  createNewScope();
+}
+{
+  "function" fctName = FunctionName()
+  ifNotExists = IfNotExists()
+  paramList = ParameterList()
+  <LEFTBRACE>
+  {
+     beginPos = token;
+  }
+  functionBodyExpr = Expression() <RIGHTBRACE>
+    {
+      endPos = token;
+      functionBody = extractFragment(beginPos.beginLine, beginPos.beginColumn, endPos.beginLine, endPos.beginColumn);
+      // TODO use fctName.library
+      signature = new FunctionSignature(fctName.dataverse, fctName.function, paramList.size());
+      getCurrentScope().addFunctionDescriptor(signature, false);
+      removeCurrentScope();
+      return new CreateFunctionStatement(signature, paramList, functionBody, ifNotExists);
+    }
+}
+
+CreateFeedStatement FeedSpecification() throws ParseException:
+{
+  Pair<Identifier,Identifier> nameComponents = null;
+  boolean ifNotExists = false;
+  String adapterName = null;
+  Map<String,String> properties = null;
+  FunctionSignature appliedFunction = null;
+  CreateFeedStatement cfs = null;
+  Pair<Identifier,Identifier> sourceNameComponents = null;
+  
+}
+{
+  (
+    "secondary" "feed"  nameComponents = QualifiedName() ifNotExists = IfNotExists()
+      <FROM> "feed" sourceNameComponents = QualifiedName() (appliedFunction = ApplyFunction())?
+      {
+        cfs = new CreateSecondaryFeedStatement(nameComponents,
+                                   sourceNameComponents, appliedFunction, ifNotExists);
+      }
+     |
+     ("primary")? "feed" nameComponents = QualifiedName() ifNotExists = IfNotExists()
+      "using" adapterName = AdapterName() properties = Configuration() (appliedFunction = ApplyFunction())?  
+       {
+        cfs = new CreatePrimaryFeedStatement(nameComponents,
+                                    adapterName, properties, appliedFunction, ifNotExists);
+       }
+  )
+    {
+      return cfs;
+    }
+}
+
+CreateFeedPolicyStatement FeedPolicySpecification() throws ParseException:
+{
+  String policyName = null;  
+  String basePolicyName = null; 
+  String sourcePolicyFile = null;
+  String definition = null;
+  boolean ifNotExists = false;
+  Map<String,String> properties = null;
+  CreateFeedPolicyStatement cfps = null;
+}
+{
+  (
+    "ingestion" "policy"  policyName = Identifier() ifNotExists = IfNotExists()
+      <FROM> 
+      ("policy" basePolicyName = Identifier() properties = Configuration() ("definition" definition = StringLiteral())?  
+      {
+        cfps = new CreateFeedPolicyStatement(policyName,
+                                   basePolicyName, properties, definition, ifNotExists);
+      }
+     | "path" sourcePolicyFile = Identifier() ("definition" definition = StringLiteral())?  
+       {
+        cfps = new CreateFeedPolicyStatement(policyName, sourcePolicyFile, definition, ifNotExists);
+       }
+     ) 
+       
+  )
+    {
+      return cfps;
+    }
+}
+
+
+
+List<VarIdentifier> ParameterList() throws ParseException:
+{
+  List<VarIdentifier> paramList = new ArrayList<VarIdentifier>();
+  VarIdentifier var = null;
+}
+{
+  <LEFTPAREN> (<VARIABLE>
+    {
+      var = new VarIdentifier();
+      var.setValue(token.image);
+      paramList.add(var);
+      getCurrentScope().addNewVarSymbolToScope(var);
+    }
+  (<COMMA> <VARIABLE>
+    {
+      var = new VarIdentifier();
+      var.setValue(token.image);
+      paramList.add(var);
+      getCurrentScope().addNewVarSymbolToScope(var);
+    }
+  )*)? <RIGHTPAREN>
+    {
+      return paramList;
+    }
+}
+
+boolean IfNotExists() throws ParseException:
+{
+}
+{
+  ( "if not exists"
+    {
+      return true;
+    }
+  )?
+    {
+      return false;
+    }
+}
+
+FunctionSignature ApplyFunction() throws ParseException:
+{
+  FunctionName functioName = null;
+  FunctionSignature funcSig = null;
+}
+{
+  "apply" "function" functioName = FunctionName()
+    {
+       String fqFunctionName = functioName.library == null ? functioName.function : functioName.library + "#" + functioName.function;
+       return new FunctionSignature(functioName.dataverse, fqFunctionName, 1);
+    }
+}
+
+String GetPolicy() throws ParseException:
+{
+  String policy = null;
+}
+{
+   "using" "policy" policy = Identifier()
+   {
+     return policy;
+   }
+
+}
+
+FunctionSignature FunctionSignature() throws ParseException:
+{
+  FunctionName fctName = null;
+  int arity = 0;
+}
+{
+  fctName = FunctionName() "@" <INTEGER_LITERAL>
+    {
+      arity = new Integer(token.image);
+      if (arity < 0 && arity != FunctionIdentifier.VARARGS) {
+        throw new ParseException(" invalid arity:" + arity);
+      }
+
+      // TODO use fctName.library
+      String fqFunctionName = fctName.library == null ? fctName.function : fctName.library + "#" + fctName.function;
+      return new FunctionSignature(fctName.dataverse, fqFunctionName, arity);
+    }
+}
+
+List<List<String>> PrimaryKey() throws ParseException:
+{
+  List<String> tmp = null;
+  List<List<String>> primaryKeyFields = new ArrayList<List<String>>();
+}
+{
+  "primary" "key" tmp = NestedField()
+    {
+      primaryKeyFields.add(tmp);
+    }
+  ( <COMMA> tmp = NestedField()
+    {
+      primaryKeyFields.add(tmp);
+    }
+  )*
+    {
+      return primaryKeyFields;
+    }
+}
+
+Statement DropStatement() throws ParseException:
+{
+  String id = null;
+  Pair<Identifier,Identifier> pairId = null;
+  Triple<Identifier,Identifier,Identifier> tripleId = null;
+  FunctionSignature funcSig = null;
+  boolean ifExists = false;
+  Statement stmt = null;
+}
+{
+  "drop"
+  (
+    <DATASET> pairId = QualifiedName() ifExists = IfExists()
+      {
+        stmt = new DropStatement(pairId.first, pairId.second, ifExists);
+      }
+    | "index" tripleId = DoubleQualifiedName() ifExists = IfExists()
+      {
+        stmt = new IndexDropStatement(tripleId.first, tripleId.second, tripleId.third, ifExists);
+      }
+    | "nodegroup" id = Identifier() ifExists = IfExists()
+      {
+        stmt = new NodeGroupDropStatement(new Identifier(id), ifExists);
+      }
+    | "type" pairId = TypeName() ifExists = IfExists()
+      {
+        stmt = new TypeDropStatement(pairId.first, pairId.second, ifExists);
+      }
+    | "dataverse" id = Identifier() ifExists = IfExists()
+      {
+        stmt = new DataverseDropStatement(new Identifier(id), ifExists);
+      }
+    | "function" funcSig = FunctionSignature() ifExists = IfExists()
+      {
+        stmt = new FunctionDropStatement(funcSig, ifExists);
+      }
+    | "feed" pairId = QualifiedName() ifExists = IfExists()
+      {
+        stmt = new FeedDropStatement(pairId.first, pairId.second, ifExists);
+      }
+  )
+  {
+    return stmt;
+  }
+}
+
+boolean IfExists() throws ParseException :
+{
+}
+{
+  ( <IF> "exists"
+    {
+      return true;
+    }
+  )?
+    {
+      return false;
+    }
+}
+
+InsertStatement InsertStatement() throws ParseException:
+{
+  Pair<Identifier,Identifier> nameComponents = null;
+  Query query;
+}
+{
+  "insert" "into" <DATASET> nameComponents = QualifiedName() query = Query()
+    {
+      query.setTopLevel(false);
+      return new InsertStatement(nameComponents.first, nameComponents.second, query, getVarCounter());
+    }
+}
+
+DeleteStatement DeleteStatement() throws ParseException:
+{
+  VariableExpr var = null;
+  Expression condition = null;
+  Pair<Identifier, Identifier> nameComponents;
+  // This is related to the new metadata lock management
+  setDataverses(new ArrayList<String>());
+  setDatasets(new ArrayList<String>());
+
+}
+{
+  "delete" var = Variable()
+    {
+      getCurrentScope().addNewVarSymbolToScope(var.getVar());
+    }
+  <FROM> <DATASET> nameComponents  = QualifiedName()
+  (<WHERE> condition = Expression())?
+    {
+      // First we get the dataverses and datasets that we want to lock
+      List<String> dataverses = getDataverses();
+      List<String> datasets = getDatasets();
+      // we remove the pointer to the dataverses and datasets
+      setDataverses(null);
+      setDatasets(null);
+      return new DeleteStatement(var, nameComponents.first, nameComponents.second,
+          condition, getVarCounter(), dataverses, datasets);
+    }
+}
+
+UpdateStatement UpdateStatement() throws ParseException:
+{
+  VariableExpr vars;
+  Expression target;
+  Expression condition;
+  UpdateClause uc;
+  List<UpdateClause> ucs = new ArrayList<UpdateClause>();
+}
+{
+  "update" vars = Variable() <IN> target = Expression()
+  <WHERE> condition = Expression()
+  <LEFTPAREN> (uc = UpdateClause()
+    {
+      ucs.add(uc);
+    }
+  (<COMMA> uc = UpdateClause()
+    {
+      ucs.add(uc);
+    }
+  )*) <RIGHTPAREN>
+    {
+      return new UpdateStatement(vars, target, condition, ucs);
+    }
+}
+
+UpdateClause UpdateClause() throws ParseException:
+{
+  Expression target = null;
+  Expression value = null ;
+  InsertStatement is = null;
+  DeleteStatement ds = null;
+  UpdateStatement us = null;
+  Expression condition = null;
+  UpdateClause ifbranch = null;
+  UpdateClause elsebranch = null;
+}
+{
+   ("set" target = Expression() <ASSIGN> value = Expression()
+   | is = InsertStatement()
+   | ds = DeleteStatement()
+   | us = UpdateStatement()
+   | <IF> <LEFTPAREN> condition = Expression() <RIGHTPAREN>
+     <THEN> ifbranch = UpdateClause()
+     [LOOKAHEAD(1) <ELSE> elsebranch = UpdateClause()]
+     {
+       return new UpdateClause(target, value, is, ds, us, condition, ifbranch, elsebranch);
+     }
+   )
+}
+
+Statement SetStatement() throws ParseException:
+{
+  String pn = null;
+  String pv = null;
+}
+{
+  "set" pn = Identifier() pv = StringLiteral()
+    {
+      return new SetStatement(pn, pv);
+    }
+}
+
+Statement WriteStatement() throws ParseException:
+{
+  String nodeName = null;
+  String fileName = null;
+  Query query;
+  String writerClass = null;
+  Pair<Identifier,Identifier> nameComponents = null;
+}
+{
+  "write" "output" "to" nodeName = Identifier() <COLON> fileName = StringLiteral()
+    ( "using" writerClass = StringLiteral() )?
+    {
+      return new WriteStatement(new Identifier(nodeName), fileName, writerClass);
+    }
+}
+
+LoadStatement LoadStatement() throws ParseException:
+{
+  Identifier dataverseName = null;
+  Identifier datasetName = null;
+  boolean alreadySorted = false;
+  String adapterName;
+  Map<String,String> properties;
+  Pair<Identifier,Identifier> nameComponents = null;
+}
+{
+  "load" <DATASET> nameComponents = QualifiedName()
+    {
+      dataverseName = nameComponents.first;
+      datasetName = nameComponents.second;
+    }
+  "using" adapterName = AdapterName() properties = Configuration()
+  ("pre-sorted"
+    {
+      alreadySorted = true;
+    }
+  )?
+    {
+      return new LoadStatement(dataverseName, datasetName, adapterName, properties, alreadySorted);
+    }
+}
+
+
+String AdapterName() throws ParseException :
+{
+  String adapterName = null;
+}
+{
+  adapterName = Identifier()
+    {
+      return adapterName;
+    }
+}
+
+Statement CompactStatement() throws ParseException:
+{
+  Pair<Identifier,Identifier> nameComponents = null;
+  Statement stmt = null;
+}
+{
+  "compact" <DATASET> nameComponents = QualifiedName()
+    {
+      stmt = new CompactStatement(nameComponents.first, nameComponents.second);
+    }
+    {
+      return stmt;
+    }
+}
+
+Statement FeedStatement() throws ParseException:
+{
+  Pair<Identifier,Identifier> feedNameComponents = null;
+  Pair<Identifier,Identifier> datasetNameComponents = null;
+
+  Map<String,String> configuration = null;
+  Statement stmt = null;
+  String policy = null;
+}
+{
+  (
+    "connect" "feed" feedNameComponents = QualifiedName() "to" <DATASET> datasetNameComponents = QualifiedName() (policy = GetPolicy())?
+      {
+        stmt = new ConnectFeedStatement(feedNameComponents, datasetNameComponents, policy, getVarCounter());
+      }
+    | "disconnect" "feed" feedNameComponents = QualifiedName() <FROM> <DATASET> datasetNameComponents = QualifiedName()
+      {
+        stmt = new DisconnectFeedStatement(feedNameComponents, datasetNameComponents);
+      }
+  )
+    {
+      return stmt;
+    }
+}
+
+Map<String,String> Configuration()  throws ParseException :
+{
+    Map<String,String> configuration = new LinkedHashMap<String,String>();
+    Pair<String, String> keyValuePair = null;
+}
+{
+  <LEFTPAREN> ( keyValuePair = KeyValuePair()
+    {
+      configuration.put(keyValuePair.first, keyValuePair.second);
+    }
+  ( <COMMA> keyValuePair = KeyValuePair()
+    {
+      configuration.put(keyValuePair.first, keyValuePair.second);
+    }
+  )* )? <RIGHTPAREN>
+    {
+      return configuration;
+    }
+}
+
+Pair<String, String> KeyValuePair() throws ParseException:
+{
+  String key;
+  String value;
+}
+{
+  <LEFTPAREN> key = StringLiteral() <EQ> value = StringLiteral() <RIGHTPAREN>
+    {
+      return new Pair<String, String>(key, value);
+    }
+}
+
+Map<String,String> Properties() throws ParseException:
+{
+  Map<String,String> properties = new HashMap<String,String>();
+  Pair<String, String> property;
+}
+{
+  ( <LEFTPAREN> property = Property()
+    {
+      properties.put(property.first, property.second);
+    }
+  ( <COMMA> property = Property()
+    {
+      properties.put(property.first, property.second);
+    }
+  )* <RIGHTPAREN> )?
+    {
+      return properties;
+    }
+}
+
+Pair<String, String> Property() throws ParseException:
+{
+  String key;
+  String value;
+}
+{
+  key = Identifier() <EQ> ( value = StringLiteral() | <INTEGER_LITERAL>
+    {
+      try {
+        value = "" + Long.valueOf(token.image);
+      } catch (NumberFormatException nfe) {
+        throw new ParseException("inapproriate value: " + token.image);
+      }
+    }
+  )
+    {
+      return new Pair<String, String>(key.toUpperCase(), value);
+    }
+}
+
+TypeExpression IndexedTypeExpr() throws ParseException:
+{
+  TypeExpression typeExpr = null;
+}
+{
+  (
+      typeExpr = TypeReference()
+    | typeExpr = OrderedListTypeDef()
+    | typeExpr = UnorderedListTypeDef()
+  )
+  {
+    return typeExpr;
+  }
+}
+
+TypeExpression TypeExpr() throws ParseException:
+{
+  TypeExpression typeExpr = null;
+}
+{
+  (
+      typeExpr = RecordTypeDef()
+    | typeExpr = TypeReference()
+    | typeExpr = OrderedListTypeDef()
+    | typeExpr = UnorderedListTypeDef()
+  )
+  {
+    return typeExpr;
+  }
+}
+
+RecordTypeDefinition RecordTypeDef() throws ParseException:
+{
+  RecordTypeDefinition recType = new RecordTypeDefinition();
+  RecordTypeDefinition.RecordKind recordKind = null;
+}
+{
+  ( "closed" { recordKind = RecordTypeDefinition.RecordKind.CLOSED; }
+    | "open" { recordKind = RecordTypeDefinition.RecordKind.OPEN; } )?
+   <LEFTBRACE>
+    {
+      String hint = getHint(token);
+      if (hint != null) {
+        String splits[] = hint.split(" +");
+        if (splits[0].equals(GEN_FIELDS_HINT)) {
+          if (splits.length != 5) {
+            throw new ParseException("Expecting: /*+ gen-fields <type> <min> <max> <prefix>*/");
+          }
+          if (!splits[1].equals("int")) {
+            throw new ParseException("The only supported type for gen-fields is int.");
+          }
+          UndeclaredFieldsDataGen ufdg = new UndeclaredFieldsDataGen(UndeclaredFieldsDataGen.Type.INT,
+             Integer.parseInt(splits[2]), Integer.parseInt(splits[3]), splits[4]);
+          recType.setUndeclaredFieldsDataGen(ufdg);
+        }
+      }
+
+    }
+        (
+          RecordField(recType)
+          ( <COMMA>  RecordField(recType) )*
+        )?
+   <RIGHTBRACE>
+   {
+      if (recordKind == null) {
+        recordKind = RecordTypeDefinition.RecordKind.OPEN;
+      }
+      recType.setRecordKind(recordKind);
+      return recType;
+   }
+}
+
+void RecordField(RecordTypeDefinition recType) throws ParseException:
+{
+  String fieldName;
+  TypeExpression type = null;
+  boolean nullable = false;
+}
+{
+  fieldName = Identifier()
+    {
+      String hint = getHint(token);
+      IRecordFieldDataGen rfdg = hint != null ? parseFieldDataGen(hint) : null;
+    }
+  <COLON> type =  TypeExpr() (<QUES> { nullable = true; } )?
+    {
+      recType.addField(fieldName, type, nullable, rfdg);
+    }
+}
+
+TypeReferenceExpression TypeReference() throws ParseException:
+{
+  String id = null;
+}
+{
+ id = Identifier()
+   {
+     if (id.equalsIgnoreCase("int")) {
+        id = "int64";
+     }
+
+     return new TypeReferenceExpression(new Identifier(id));
+   }
+}
+
+OrderedListTypeDefinition OrderedListTypeDef() throws ParseException:
+{
+  TypeExpression type = null;
+}
+{
+  <LEFTBRACKET>
+    ( type =  TypeExpr() )
+  <RIGHTBRACKET>
+  {
+    return new OrderedListTypeDefinition(type);
+  }
+}
+
+
+UnorderedListTypeDefinition UnorderedListTypeDef() throws ParseException:
+{
+  TypeExpression type = null;
+}
+{
+  <LEFTDBLBRACE>
+    ( type =  TypeExpr() )
+  <RIGHTDBLBRACE>
+  {
+    return new UnorderedListTypeDefinition(type);
+  }
+}
+
+FunctionName FunctionName() throws ParseException:
+{
+  String first = null;
+  String second = null;
+  String third = null;
+  boolean secondAfterDot = false;
+}
+{
+  first = Identifier() 
+  {
+    FunctionName result = new FunctionName();
+    result.hint = getHint(token);
+  } 
+  ( <DOT> second = Identifier()
+    {
+      secondAfterDot = true;
+    }
+  ("#" third = Identifier())? | "#" second = Identifier() )?
+    {
+      if (second == null) {
+        result.dataverse = defaultDataverse;
+        result.library = null;
+        result.function = first;
+      } else if (third == null) {
+        if (secondAfterDot) {
+          result.dataverse = first;
+          result.library   = null;
+          result.function = second;
+        } else {
+          result.dataverse = defaultDataverse;
+          result.library   = first;
+          result.function = second;
+        }
+      } else {
+        result.dataverse = first;
+        result.library   = second;
+        result.function  = third;
+      }
+
+      if (result.function.equalsIgnoreCase("int")) {
+            result.function = "int64";
+      }
+      return result;
+    }
+}
+
+
+Pair<Identifier,Identifier> TypeName() throws ParseException:
+{
+  Pair<Identifier,Identifier> name = null;
+}
+{
+  name = QualifiedName()
+    {
+      if (name.first == null) {
+        name.first = new Identifier(defaultDataverse);
+      }
+      return name;
+    }
+}
+
+String Identifier() throws ParseException:
+{
+  String lit = null;
+}
+{
+  (<IDENTIFIER>
+    {
+      return token.image;
+    }
+  | lit = StringLiteral()
+    {
+      return lit;
+    }
+  )
+}
+
+Pair<List<String>, TypeExpression> OpenField() throws ParseException:
+{
+  TypeExpression fieldType = null;
+  List<String> fieldList = null;
+}
+{
+  fieldList = NestedField()
+  ( <COLON> fieldType =  IndexedTypeExpr() )?
+  {
+    return new Pair<List<String>, TypeExpression>(fieldList, fieldType);
+  }
+}
+
+List<String> NestedField() throws ParseException:
+{
+  List<String> exprList = new ArrayList<String>();
+  String lit = null;
+}
+{
+  lit = Identifier()
+  {
+    exprList.add(lit);
+  }
+  (<DOT>
+    lit = Identifier()
+    {
+      exprList.add(lit);
+    }
+  )*
+  {
+    return exprList;
+  }
+}
+
+
+
+String StringLiteral() throws ParseException:
+{
+}
+{
+  <STRING_LITERAL>
+    {
+      return removeQuotesAndEscapes(token.image);
+    }
+}
+
+Pair<Identifier,Identifier> QualifiedName() throws ParseException:
+{
+  String first = null;
+  String second = null;
+}
+{
+  first = Identifier() (<DOT> second = Identifier())?
+  {
+    Identifier id1 = null;
+    Identifier id2 = null;
+    if (second == null) {
+      id2 = new Identifier(first);
+    } else
+    {
+      id1 = new Identifier(first);
+      id2 = new Identifier(second);
+    }
+    return new Pair<Identifier,Identifier>(id1, id2);
+  }
+}
+
+Triple<Identifier,Identifier,Identifier> DoubleQualifiedName() throws ParseException:
+{
+  String first = null;
+  String second = null;
+  String third = null;
+}
+{
+  first = Identifier() <DOT> second = Identifier() (<DOT> third = Identifier())?
+  {
+    Identifier id1 = null;
+    Identifier id2 = null;
+    Identifier id3 = null;
+    if (third == null) {
+      id2 = new Identifier(first);
+      id3 = new Identifier(second);
+    } else {
+      id1 = new Identifier(first);
+      id2 = new Identifier(second);
+      id3 = new Identifier(third);
+    }
+    return new Triple<Identifier,Identifier,Identifier>(id1, id2, id3);
+  }
+}
+
+FunctionDecl FunctionDeclaration() throws ParseException:
+{
+  FunctionDecl funcDecl;
+  FunctionSignature signature;
+  String functionName;
+  List<VarIdentifier> paramList = new ArrayList<VarIdentifier>();
+  Expression funcBody;
+  createNewScope();
+}
+{
+  "declare" "function" functionName = Identifier()
+  paramList = ParameterList()
+  <LEFTBRACE> funcBody = Expression() <RIGHTBRACE>
+    {
+      signature = new FunctionSignature(defaultDataverse, functionName, paramList.size());
+      getCurrentScope().addFunctionDescriptor(signature, false);
+      funcDecl = new FunctionDecl(signature, paramList, funcBody);
+      removeCurrentScope();
+      return funcDecl;
+    }
+}
+
+
+Query Query() throws ParseException:
+{
+  Query query = new Query();
+  // we set the pointers to the dataverses and datasets lists to fill them with entities to be locked
+  setDataverses(query.getDataverses());
+  setDatasets(query.getDatasets());
+  Expression expr;
+}
+{
+  expr = Expression()
+    {
+      query.setBody(expr);
+      query.setVarCounter(getVarCounter());
+      // we remove the pointers to the locked entities before we return the query object
+      setDataverses(null);
+      setDatasets(null);
+      return query;
+    }
+
+}
+
+
+
+Expression Expression():
+{
+  Expression expr = null;
+  Expression exprP = null;
+}
+{
+(
+
+//OperatorExpr | IfThenElse | FLWOGRExpression | QuantifiedExpression
+    expr = OperatorExpr()
+    | expr = IfThenElse()
+    | expr = FLWOGR()
+    | expr = QuantifiedExpression()
+
+
+)
+    {
+      return (exprP==null) ? expr : exprP;
+    }
+}
+
+
+
+Expression OperatorExpr()throws ParseException:
+{
+  OperatorExpr op = null;
+  Expression operand = null;
+}
+{
+    operand = AndExpr()
+    (
+
+      <OR>
+      {
+        if (op == null) {
+          op = new OperatorExpr();
+          op.addOperand(operand);
+        op.setCurrentop(true);
+        }
+      op.addOperator(token.image);
+    }
+
+    operand = AndExpr()
+    {
+      op.addOperand(operand);
+    }
+
+    )*
+
+    {
+      return op==null? operand: op;
+    }
+}
+
+Expression AndExpr()throws ParseException:
+{
+  OperatorExpr op = null;
+  Expression operand = null;
+}
+{
+    operand = RelExpr()
+    (
+
+      <AND>
+      {
+        if (op == null) {
+          op = new OperatorExpr();
+          op.addOperand(operand);
+        op.setCurrentop(true);
+        }
+      op.addOperator(token.image);
+    }
+
+    operand = RelExpr()
+    {
+      op.addOperand(operand);
+    }
+
+    )*
+
+    {
+      return op==null? operand: op;
+    }
+}
+
+
+
+Expression RelExpr()throws ParseException:
+{
+  OperatorExpr op = null;
+  Expression operand = null;
+  boolean broadcast = false;
+  IExpressionAnnotation annotation = null;
+}
+{
+    operand = AddExpr()
+    {
+      if (operand instanceof VariableExpr) {
+        String hint = getHint(token);
+        if (hint != null && hint.equals(BROADCAST_JOIN_HINT)) {
+          broadcast = true;
+        }
+      }
+    }
+
+    (
+      LOOKAHEAD(2)( <LT> | <GT> | <LE> | <GE> | <EQ> | <NE> |<SIMILAR>)
+        {
+          String mhint = getHint(token);
+          if (mhint != null) {
+            if (mhint.equals(INDEXED_NESTED_LOOP_JOIN_HINT)) {
+            annotation = IndexedNLJoinExpressionAnnotation.INSTANCE;
+          } else if (mhint.equals(SKIP_SECONDARY_INDEX_SEARCH_HINT)) {
+            annotation = SkipSecondaryIndexSearchExpressionAnnotation.INSTANCE;
+          }
+        }
+          if (op == null) {
+            op = new OperatorExpr();
+            op.addOperand(operand, broadcast);
+          op.setCurrentop(true);
+          broadcast = false;
+          }
+        op.addOperator(token.image);
+      }
+
+       operand = AddExpr()
+      {
+         broadcast = false;
+         if (operand instanceof VariableExpr) {
+           String hint = getHint(token);
+           if (hint != null && hint.equals(BROADCAST_JOIN_HINT)) {
+             broadcast = true;
+           }
+         }
+         op.addOperand(operand, broadcast);
+      }
+    )?
+
+     {
+       if (annotation != null) {
+         op.addHint(annotation);
+       }
+       return op==null? operand: op;
+     }
+}
+
+Expression AddExpr()throws ParseException:
+{
+  OperatorExpr op = null;
+  Expression operand = null;
+}
+{
+    operand = MultExpr()
+
+    ( (<PLUS> | <MINUS>)
+      {
+        if (op == null) {
+          op = new OperatorExpr();
+        op.addOperand(operand);
+        op.setCurrentop(true);
+        }
+      ((OperatorExpr)op).addOperator(token.image);
+    }
+
+    operand = MultExpr()
+    {
+      op.addOperand(operand);
+    }
+    )*
+
+    {
+       return op==null? operand: op;
+     }
+}
+
+Expression MultExpr()throws ParseException:
+{
+  OperatorExpr op = null;
+  Expression operand = null;
+}
+{
+    operand = UnionExpr()
+
+    (( <MUL> | <DIV> | <MOD> | <CARET> | <IDIV>)
+      {
+        if (op == null) {
+          op = new OperatorExpr();
+        op.addOperand(operand);
+        op.setCurrentop(true);
+        }
+      op.addOperator(token.image);
+    }
+    operand = UnionExpr()
+    {
+       op.addOperand(operand);
+    }
+    )*
+
+     {
+       return op==null?operand:op;
+     }
+}
+
+Expression UnionExpr() throws ParseException:
+{
+    UnionExpr union = null;
+    Expression operand1 = null;
+    Expression operand2 = null;
+}
+{
+   operand1 = UnaryExpr()
+   (<UNION>
+       (operand2 = UnaryExpr()) {
+          if (union == null) {
+             union = new UnionExpr();
+             union.addExpr(operand1);
+          }
+          union.addExpr(operand2);
+       } )*
+   {
+     return (union == null)? operand1: union;
+   }
+}
+
+Expression UnaryExpr() throws ParseException:
+{
+    Expression uexpr = null;
+    Expression expr = null;
+}
+{
+    ( (<PLUS> | <MINUS>)
+    {
+          uexpr = new UnaryExpr();
+        if("+".equals(token.image))
+            ((UnaryExpr)uexpr).setSign(Sign.POSITIVE);
+        else if("-".equals(token.image))
+            ((UnaryExpr)uexpr).setSign(Sign.NEGATIVE);
+        else
+            throw new ParseException();
+    }
+    )?
+
+    expr = ValueExpr()
+    {
+        if(uexpr!=null){
+            ((UnaryExpr)uexpr).setExpr(expr);
+            return uexpr;
+        }
+        else{
+            return expr;
+        }
+    }
+}
+
+Expression ValueExpr()throws ParseException:
+{
+  Expression expr = null;
+  Identifier ident = null;
+  AbstractAccessor fa = null;
+  Expression indexExpr = null;
+}
+{
+  expr = PrimaryExpr() ( ident = Field()
+    {
+      fa = (fa == null ? new FieldAccessor(expr, ident)
+                       : new FieldAccessor(fa, ident));
+    }
+  | indexExpr = Index()
+    {
+      fa = (fa == null ? new IndexAccessor(expr, indexExpr)
+                       : new IndexAccessor(fa, indexExpr));
+     }
+  )*
+    {
+      return fa == null ? expr : fa;
+    }
+}
+
+Identifier Field() throws ParseException:
+{
+  String ident = null;
+}
+{
+  <DOT> ident = Identifier()
+    {
+      return new Identifier(ident);
+    }
+}
+
+Expression Index() throws ParseException:
+{
+    Expression expr = null;
+}
+{
+  <LEFTBRACKET> ( expr = Expression()
+    {
+        if(expr.getKind() == Expression.Kind.LITERAL_EXPRESSION)
+        {
+            Literal lit = ((LiteralExpr)expr).getValue();
+            if(lit.getLiteralType() != Literal.Type.INTEGER &&
+               lit.getLiteralType() != Literal.Type.LONG) {
+                throw new ParseException("Index should be an INTEGER");
+            }
+        }
+    }
+
+      | <QUES> // ANY
+
+      )
+
+   <RIGHTBRACKET>
+    {
+      return expr;
+    }
+}
+
+
+Expression PrimaryExpr()throws ParseException:
+{
+  Expression expr = null;
+}
+{
+  ( LOOKAHEAD(2)
+    expr = FunctionCallExpr()
+  | expr = Literal()
+  | expr = DatasetAccessExpression()
+  | expr = VariableRef()
+    {
+      if(((VariableExpr)expr).getIsNewVar() == true)
+        throw new ParseException("can't find variable " + ((VariableExpr)expr).getVar());
+    }
+  | expr = ListConstructor()
+  | expr = RecordConstructor()
+  | expr = ParenthesizedExpression()
+  )
+    {
+      return expr;
+    }
+}
+
+Expression Literal() throws ParseException:
+{
+  LiteralExpr lit = new LiteralExpr();
+  String str = null;
+}
+{
+  ( str = StringLiteral()
+    {
+      lit.setValue(new StringLiteral(str));
+    }
+  | <INTEGER_LITERAL>
+    {
+      lit.setValue(new LongIntegerLiteral(new Long(token.image)));
+    }
+  | <FLOAT_LITERAL>
+    {
+      lit.setValue(new FloatLiteral(new Float(token.image)));
+    }
+  | <DOUBLE_LITERAL>
+    {
+      lit.setValue(new DoubleLiteral(new Double(token.image)));
+    }
+  | <NULL>
+    {
+      lit.setValue(NullLiteral.INSTANCE);
+    }
+  | <TRUE>
+    {
+      lit.setValue(TrueLiteral.INSTANCE);
+    }
+  | <FALSE>
+    {
+      lit.setValue(FalseLiteral.INSTANCE);
+    }
+  )
+    {
+      return lit;
+    }
+}
+
+
+VariableExpr VariableRef() throws ParseException:
+{
+    VariableExpr varExp = new VariableExpr();
+    VarIdentifier var = new VarIdentifier();
+}
+{
+  <VARIABLE>
+    {
+     String varName = token.image;
+     Identifier ident = lookupSymbol(varName);
+     if (isInForbiddenScopes(varName)) {
+       throw new ParseException("Inside limit clauses, it is disallowed to reference a variable having the same name as any variable bound in the same scope as the limit clause.");
+     }
+     if(ident != null) { // exist such ident
+       varExp.setIsNewVar(false);
+       varExp.setVar((VarIdentifier)ident);
+     } else {
+       varExp.setVar(var);
+     }
+     var.setValue(varName);
+     return varExp;
+    }
+}
+
+
+VariableExpr Variable() throws ParseException:
+{
+    VariableExpr varExp = new VariableExpr();
+    VarIdentifier var = new VarIdentifier();
+}
+{
+  <VARIABLE>
+    {
+     Identifier ident = lookupSymbol(token.image);
+     if(ident != null) { // exist such ident
+       varExp.setIsNewVar(false);
+     }
+     varExp.setVar(var);
+     var.setValue(token.image);
+     return varExp;
+    }
+}
+
+Expression ListConstructor() throws ParseException:
+{
+    Expression expr = null;
+}
+{
+    (
+        expr = OrderedListConstructor() | expr = UnorderedListConstructor()
+    )
+
+    {
+      return expr;
+    }
+}
+
+
+ListConstructor OrderedListConstructor() throws ParseException:
+{
+      ListConstructor expr = new ListConstructor();
+      List<Expression> exprList = null;
+      expr.setType(ListConstructor.Type.ORDERED_LIST_CONSTRUCTOR);
+}
+{
+    <LEFTBRACKET> exprList = ExpressionList() <RIGHTBRACKET>
+    {
+      expr.setExprList(exprList);
+      return expr;
+    }
+}
+
+ListConstructor UnorderedListConstructor() throws ParseException:
+{
+      ListConstructor expr = new ListConstructor();
+      List<Expression> exprList = null;
+      expr.setType(ListConstructor.Type.UNORDERED_LIST_CONSTRUCTOR);
+}
+{
+    <LEFTDBLBRACE> exprList = ExpressionList() <RIGHTDBLBRACE>
+    {
+      expr.setExprList(exprList);
+      return expr;
+    }
+}
+
+List<Expression> ExpressionList() throws ParseException:
+{
+      Expression expr = null;
+      List<Expression> list = null;
+      List<Expression> exprList = new ArrayList<Expression>();
+}
+{
+    (
+      expr = Expression() { exprList.add(expr); }
+      (LOOKAHEAD(1) <COMMA> list = ExpressionList() { exprList.addAll(list); })?
+    )?
+    (LOOKAHEAD(1) Comma())?
+    {
+        return exprList;
+    }
+}
+
+void Comma():
+{}
+{
+   <COMMA>
+}
+
+RecordConstructor RecordConstructor() throws ParseException:
+{
+      RecordConstructor expr = new RecordConstructor();
+      FieldBinding tmp = null;
+      List<FieldBinding> fbList = new ArrayList<FieldBinding>();
+}
+{
+    <LEFTBRACE> (tmp = FieldBinding()
+    {
+      fbList.add(tmp);
+    }
+    (<COMMA> tmp = FieldBinding() { fbList.add(tmp);  })*)? <RIGHTBRACE>
+    {
+      expr.setFbList(fbList);
+      return expr;
+    }
+}
+
+FieldBinding FieldBinding() throws ParseException:
+{
+    FieldBinding fb = new FieldBinding();
+    Expression left, right;
+}
+{
+    left = Expression() <COLON> right = Expression()
+    {
+      fb.setLeftExpr(left);
+      fb.setRightExpr(right);
+      return fb;
+    }
+}
+
+
+Expression FunctionCallExpr() throws ParseException:
+{
+  CallExpr callExpr;
+  List<Expression> argList = new ArrayList<Expression>();
+  Expression tmp;
+  int arity = 0;
+  FunctionName funcName = null;
+  String hint = null;
+}
+{
+  funcName = FunctionName()
+    {
+      hint = funcName.hint;
+    }
+  <LEFTPAREN> (tmp = Expression()
+    {
+      argList.add(tmp);
+      arity ++;
+    }
+  (<COMMA> tmp = Expression()
+    {
+      argList.add(tmp);
+      arity++;
+    }
+  )*)? <RIGHTPAREN>
+    {
+      // TODO use funcName.library
+      String fqFunctionName = funcName.library == null ? funcName.function : funcName.library + "#" + funcName.function;
+      FunctionSignature signature
+        = lookupFunctionSignature(funcName.dataverse, fqFunctionName, arity);
+      if (signature == null) {
+        signature = new FunctionSignature(funcName.dataverse, fqFunctionName, arity);
+      }
+      callExpr = new CallExpr(signature,argList);
+      if (hint != null) {
+        if (hint.startsWith(INDEXED_NESTED_LOOP_JOIN_HINT)) {
+          callExpr.addHint(IndexedNLJoinExpressionAnnotation.INSTANCE);
+        } else if (hint.startsWith(SKIP_SECONDARY_INDEX_SEARCH_HINT)) {
+          callExpr.addHint(SkipSecondaryIndexSearchExpressionAnnotation.INSTANCE);
+        }
+      }
+      return callExpr;
+    }
+}
+
+
+Expression DatasetAccessExpression() throws ParseException:
+{
+  String funcName;
+  String arg1 = null;
+  String arg2 = null;
+  Expression nameArg;
+}
+{
+  <DATASET>
+    {
+      funcName = token.image;
+    }
+  ( ( arg1 = Identifier() ( <DOT> arg2 = Identifier() )? )
+    {
+      String name = arg2 == null ? arg1 : arg1 + "." + arg2;
+      LiteralExpr ds = new LiteralExpr();
+      ds.setValue( new StringLiteral(name) );
+      nameArg = ds;
+      if(arg2 != null){
+          addDataverse(arg1.toString());
+          addDataset(name);
+      } else {
+          addDataset(defaultDataverse + "." + name);
+      }
+    }
+  | ( <LEFTPAREN> nameArg = Expression() <RIGHTPAREN> ) )
+    {
+      String dataverse = MetadataConstants.METADATA_DATAVERSE_NAME;
+      FunctionSignature signature = lookupFunctionSignature(dataverse, funcName, 1);
+      if (signature == null) {
+        signature = new FunctionSignature(dataverse, funcName, 1);
+      }
+      List<Expression> argList = new ArrayList<Expression>();
+      argList.add(nameArg);
+      return new CallExpr(signature, argList);
+    }
+}
+
+Expression ParenthesizedExpression() throws ParseException:
+{
+  Expression expr;
+}
+{
+    <LEFTPAREN> expr = Expression() <RIGHTPAREN>
+    {
+      return expr;
+    }
+}
+
+Expression IfThenElse() throws ParseException:
+{
+  Expression condExpr;
+  Expression thenExpr;
+  Expression elseExpr;
+  IfExpr ifExpr = new IfExpr();
+}
+{
+    <IF> <LEFTPAREN> condExpr = Expression() <RIGHTPAREN> <THEN> thenExpr = Expression() <ELSE> elseExpr = Expression()
+
+    {
+      ifExpr.setCondExpr(condExpr);
+      ifExpr.setThenExpr(thenExpr);
+      ifExpr.setElseExpr(elseExpr);
+      return ifExpr;
+    }
+}
+
+Expression  FLWOGR() throws ParseException:
+{
+    FLWOGRExpression flworg = new FLWOGRExpression();
+    List<Clause> clauseList = new ArrayList<Clause>();
+    Expression returnExpr;
+    Clause tmp;
+    createNewScope();
+}
+{
+     (tmp = ForClause()  {clauseList.add(tmp);} | tmp = LetClause() {clauseList.add(tmp);})
+      (tmp = Clause() {clauseList.add(tmp);})* (<RETURN>|<SELECT>) returnExpr = Expression()
+
+     {
+       flworg.setClauseList(clauseList);
+       flworg.setReturnExpr(returnExpr);
+       removeCurrentScope();
+       return flworg;
+     }
+}
+
+Clause Clause()throws ParseException :
+{
+  Clause clause;
+}
+{
+    (
+         clause = ForClause()
+       | clause = LetClause()
+       | clause = WhereClause()
+       | clause = OrderbyClause()
+       | clause = GroupClause()
+       | clause = LimitClause()
+       | clause = DistinctClause()
+    )
+    {
+      return clause;
+    }
+}
+
+Clause ForClause()throws ParseException :
+{
+    ForClause fc = new ForClause();
+    VariableExpr varExp;
+    VariableExpr varPos = null;
+    Expression inExp;
+    extendCurrentScope();
+}
+{
+    (<FOR>|<FROM>) varExp = Variable() (<AT> varPos = Variable())?  <IN> ( inExp = Expression() )
+    {
+      fc.setVarExpr(varExp);
+      getCurrentScope().addNewVarSymbolToScope(varExp.getVar());
+      fc.setInExpr(inExp);
+      if (varPos != null) {
+        fc.setPosExpr(varPos);
+        getCurrentScope().addNewVarSymbolToScope(varPos.getVar());
+      }
+      return fc;
+    }
+}
+
+Clause LetClause() throws ParseException:
+{
+    LetClause lc = new LetClause();
+    VariableExpr varExp;
+    Expression beExp;
+    extendCurrentScope();
+}
+{
+    (<LET>|<WITH>) varExp = Variable() <ASSIGN> beExp = Expression()
+    {
+      getCurrentScope().addNewVarSymbolToScope(varExp.getVar());
+      lc.setVarExpr(varExp);
+      lc.setBindingExpr(beExp);
+      return lc;
+    }
+}
+
+Clause WhereClause()throws ParseException :
+{
+  WhereClause wc = new WhereClause();
+  Expression whereExpr;
+}
+{
+    <WHERE> whereExpr = Expression()
+    {
+      wc.setWhereExpr(whereExpr);
+      return wc;
+    }
+}
+
+Clause OrderbyClause()throws ParseException :
+{
+    OrderbyClause oc = new OrderbyClause();
+    Expression orderbyExpr;
+    List<Expression> orderbyList = new ArrayList<Expression>();
+    List<OrderbyClause.OrderModifier> modifierList = new ArrayList<OrderbyClause.OrderModifier >();
+    int numOfOrderby = 0;
+}
+{
+  (
+    <ORDER>
+      {
+        String hint = getHint(token);
+        if (hint != null) {
+          if (hint.startsWith(INMEMORY_HINT)) {
+            String splits[] = hint.split(" +");
+            int numFrames = Integer.parseInt(splits[1]);
+            int numTuples = Integer.parseInt(splits[2]);
+            oc.setNumFrames(numFrames);
+            oc.setNumTuples(numTuples);
+          }
+          if (hint.startsWith(RANGE_HINT)) {
+            try{
+              oc.setRangeMap(RangeMapBuilder.parseHint(hint.substring(RANGE_HINT.length())));
+            } catch (AsterixException e) {
+              throw new ParseException(e.getMessage());
+            }
+          }
+        }
+      }
+    <BY> orderbyExpr = Expression()
+    {
+      orderbyList.add(orderbyExpr);
+      OrderbyClause.OrderModifier modif = OrderbyClause.OrderModifier.ASC;
+    }
+    ( (<ASC> { modif = OrderbyClause.OrderModifier.ASC; })
+    | (<DESC> { modif = OrderbyClause.OrderModifier.DESC; }))?
+    {
+      modifierList.add(modif);
+    }
+
+    (<COMMA> orderbyExpr = Expression()
+    {
+      orderbyList.add(orderbyExpr);
+      modif = OrderbyClause.OrderModifier.ASC;
+    }
+    ( (<ASC> { modif = OrderbyClause.OrderModifier.ASC; })
+    | (<DESC> { modif = OrderbyClause.OrderModifier.DESC; }))?
+    {
+      modifierList.add(modif);
+    }
+    )*
+)
+    {
+      oc.setModifierList(modifierList);
+      oc.setOrderbyList(orderbyList);
+      return oc;
+    }
+}
+Clause GroupClause()throws ParseException :
+{
+      GroupbyClause gbc = new GroupbyClause();
+      // GbyVariableExpressionPair pair = new GbyVariableExpressionPair();
+     List<GbyVariableExpressionPair> vePairList = new ArrayList<GbyVariableExpressionPair>();
+    List<GbyVariableExpressionPair> decorPairList = new ArrayList<GbyVariableExpressionPair>();
+    List<VariableExpr> withVarList= new ArrayList<VariableExpr>();
+    VariableExpr var = null;
+    VariableExpr withVar = null;
+    Expression expr = null;
+    VariableExpr decorVar = null;
+    Expression decorExpr = null;
+}
+{
+      {
+        Scope newScope = extendCurrentScopeNoPush(true);
+        // extendCurrentScope(true);
+      }
+    <GROUP>
+      {
+         String hint = getHint(token);
+         if (hint != null && hint.equals(HASH_GROUP_BY_HINT)) {
+           gbc.setHashGroupByHint(true);
+         }
+      }
+    <BY> (LOOKAHEAD(2)  var = Variable()
+    {
+      newScope.addNewVarSymbolToScope(var.getVar());
+    } <ASSIGN>)?
+    expr = Expression()
+       {
+         GbyVariableExpressionPair pair1 = new GbyVariableExpressionPair(var, expr);
+         vePairList.add(pair1);
+       }
+    (<COMMA> ( LOOKAHEAD(2) var = Variable()
+    {
+      newScope.addNewVarSymbolToScope(var.getVar());
+    } <ASSIGN>)?
+        expr = Expression()
+         {
+           GbyVariableExpressionPair pair2 = new GbyVariableExpressionPair(var, expr);
+           vePairList.add(pair2);
+         }
+        )*
+    (<DECOR> decorVar = Variable() <ASSIGN> decorExpr = Expression()
+       {
+         newScope.addNewVarSymbolToScope(decorVar.getVar());
+         GbyVariableExpressionPair pair3 = new GbyVariableExpressionPair(decorVar, decorExpr);
+         decorPairList.add(pair3);
+       }
+      (<COMMA> <DECOR> decorVar = Variable() <ASSIGN> decorExpr = Expression()
+           {
+             newScope.addNewVarSymbolToScope(decorVar.getVar());
+             GbyVariableExpressionPair pair4 = new GbyVariableExpressionPair(decorVar, decorExpr);
+             decorPairList.add(pair4);
+           }
+       )*
+    )?
+    (<WITH>|<KEEPING>) withVar = VariableRef()
+    {
+      if(withVar.getIsNewVar()==true)
+          throw new ParseException("can't find variable " + withVar.getVar());
+      withVarList.add(withVar);
+      newScope.addNewVarSymbolToScope(withVar.getVar());
+    }
+    (<COMMA> withVar = VariableRef()
+    {
+      if(withVar.getIsNewVar()==true)
+          throw new ParseException("can't find variable " + withVar.getVar());
+      withVarList.add(withVar);
+      newScope.addNewVarSymbolToScope(withVar.getVar());
+    })*
+    {
+      gbc.setGbyPairList(vePairList);
+      gbc.setDecorPairList(decorPairList);
+      gbc.setWithVarList(withVarList);
+      replaceCurrentScope(newScope);
+      return gbc;
+    }
+}
+
+
+LimitClause LimitClause() throws ParseException:
+{
+    LimitClause lc = new LimitClause();
+    Expression expr;
+    pushForbiddenScope(getCurrentScope());
+}
+{
+    <LIMIT> expr = Expression()    { lc.setLimitExpr(expr);    }
+    (<OFFSET> expr = Expression() { lc.setOffset(expr);    })?
+
+  {
+    popForbiddenScope();
+    return lc;
+  }
+}
+
+DistinctClause DistinctClause() throws ParseException:
+{
+  List<Expression> exprs = new ArrayList<Expression>();
+  Expression expr;
+}
+{
+  <DISTINCT> <BY> expr = Expression()
+  {
+    exprs.add(expr);
+  }
+  (<COMMA> expr = Expression()
+      {
+          exprs.add(expr);
+      }
+  )*
+  {
+      return new DistinctClause(exprs);
+  }
+}
+
+QuantifiedExpression QuantifiedExpression()throws ParseException:
+{
+  QuantifiedExpression qc = new QuantifiedExpression();
+  List<QuantifiedPair> quantifiedList = new ArrayList<QuantifiedPair>();
+  Expression satisfiesExpr;
+  VariableExpr var;
+  Expression inExpr;
+  QuantifiedPair pair;
+}
+{
+  {
+    createNewScope();
+  }
+
+   (      (<SOME>  {  qc.setQuantifier(QuantifiedExpression.Quantifier.SOME);	})
+        | (<EVERY> {  qc.setQuantifier(QuantifiedExpression.Quantifier.EVERY);	}))
+    var = Variable() <IN> inExpr = Expression()
+    {
+      pair = new QuantifiedPair(var, inExpr);
+      getCurrentScope().addNewVarSymbolToScope(var.getVar());
+      quantifiedList.add(pair);
+    }
+    (
+    <COMMA> var = Variable() <IN> inExpr = Expression()
+    {
+      pair = new QuantifiedPair(var, inExpr);
+      getCurrentScope().addNewVarSymbolToScope(var.getVar());
+      quantifiedList.add(pair);
+    }
+    )*
+     <SATISFIES> satisfiesExpr = Expression()
+     {
+       qc.setSatisfiesExpr(satisfiesExpr);
+       qc.setQuantifiedList(quantifiedList);
+       removeCurrentScope();
+       return qc;
+     }
+}
+
+TOKEN_MGR_DECLS:
+{
+    public int commentDepth = 0;
+    public IntStack lexerStateStack = new IntStack();
+
+    public void pushState() {
+      lexerStateStack.push( curLexState );
+    }
+
+    public void popState(String token) {
+      if (lexerStateStack.size() > 0) {
+         SwitchTo( lexerStateStack.pop() );
+      } else {
+         int errorLine = input_stream.getEndLine();
+         int errorColumn = input_stream.getEndColumn();
+         String msg = "Lexical error at line " + errorLine + ", column " + errorColumn + ". Encountered \"" + token
+             + "\" but state stack is empty.";
+         throw new TokenMgrError(msg, -1);
+      }
+    }
+}
+
+<DEFAULT,IN_DBL_BRACE>
+TOKEN :
+{
+    <ASC : "asc">
+  | <AT : "at">
+  | <BY : "by">
+  | <DATASET : "dataset">
+  | <DECOR : "decor">
+  | <DESC : "desc">
+  | <DISTINCT : "distinct">
+  | <ELSE : "else">
+  | <EVERY : "every">
+  | <FOR : "for">
+  | <FROM : "from">
+  | <GROUP : "group">
+  | <IF : "if">
+  | <IN : "in">
+  | <LET : "let">
+  | <LIMIT : "limit">
+  | <OFFSET : "offset">
+  | <ORDER : "order">
+  | <RETURN : "return">
+  | <SATISFIES : "satisfies">
+  | <SELECT : "select">
+  | <SOME : "some">
+  | <THEN : "then">
+  | <UNION : "union">
+  | <WHERE : "where">
+  | <WITH : "with">
+  | <KEEPING : "keeping">
+}
+
+<DEFAULT,IN_DBL_BRACE>
+TOKEN :
+{
+    <CARET : "^">
+  | <DIV : "/">
+  | <IDIV : "idiv">
+  | <MINUS : "-">
+  | <MOD : "%">
+  | <MUL : "*">
+  | <PLUS : "+">
+
+  | <LEFTPAREN : "(">
+  | <RIGHTPAREN : ")">
+  | <LEFTBRACKET : "[">
+  | <RIGHTBRACKET : "]">
+
+  | <COLON : ":">
+  | <COMMA : ",">
+  | <DOT : ".">
+  | <QUES : "?">
+
+  | <LT : "<">
+  | <GT : ">">
+  | <LE : "<=">
+  | <GE : ">=">
+  | <EQ : "=">
+  | <NE : "!=">
+  | <SIMILAR : "~=">
+  | <ASSIGN : ":=">
+
+  | <AND : "and">
+  | <OR : "or">
+}
+
+<DEFAULT,IN_DBL_BRACE>
+TOKEN :
+{
+    <LEFTBRACE : "{"> { pushState(); } : DEFAULT
+}
+
+<DEFAULT>
+TOKEN :
+{
+    <RIGHTBRACE : "}"> { popState("}"); }
+}
+
+<DEFAULT,IN_DBL_BRACE>
+TOKEN :
+{
+    <LEFTDBLBRACE : "{{"> { pushState(); } : IN_DBL_BRACE
+}
+
+<IN_DBL_BRACE>
+TOKEN :
+{
+    <RIGHTDBLBRACE : "}}"> { popState("}}"); }
+}
+
+<DEFAULT,IN_DBL_BRACE>
+TOKEN :
+{
+    <INTEGER_LITERAL : (<DIGIT>)+ >
+}
+
+<DEFAULT,IN_DBL_BRACE>
+TOKEN :
+{
+    <NULL : "null">
+  | <TRUE : "true">
+  | <FALSE : "false">
+}
+
+<DEFAULT,IN_DBL_BRACE>
+TOKEN :
+{
+    <#DIGIT : ["0" - "9"]>
+}
+
+<DEFAULT,IN_DBL_BRACE>
+TOKEN:
+{
+    < DOUBLE_LITERAL: <DIGITS>
+        | <DIGITS> ( "." <DIGITS> )?
+        | "." <DIGITS>
+    >
+  | < FLOAT_LITERAL: <DIGITS> ( "f" | "F" )
+        | <DIGITS> ( "." <DIGITS> ( "f" | "F" ) )?
+        | "." <DIGITS> ( "f" | "F" )
+    >
+  | <DIGITS : (<DIGIT>)+ >
+}
+
+<DEFAULT,IN_DBL_BRACE>
+TOKEN :
+{
+    <#LETTER : ["A" - "Z", "a" - "z"]>
+  | <SPECIALCHARS : ["$", "_", "-"]>
+}
+
+<DEFAULT,IN_DBL_BRACE>
+TOKEN :
+{
+    // backslash u + 4 hex digits escapes are handled in the underlying JavaCharStream
+    <STRING_LITERAL : ("\"" (
+          <EscapeQuot>
+        | <EscapeBslash>
+        | <EscapeSlash>
+        | <EscapeBspace>
+        | <EscapeFormf>
+        | <EscapeNl>
+        | <EscapeCr>
+        | <EscapeTab>
+        | ~["\"","\\"])* "\"")
+      | ("\'"(
+          <EscapeApos>
+        | <EscapeBslash>
+        | <EscapeSlash>
+        | <EscapeBspace>
+        | <EscapeFormf>
+        | <EscapeNl>
+        | <EscapeCr>
+        | <EscapeTab>
+        | ~["\'","\\"])* "\'")>
+  | < #EscapeQuot: "\\\"" >
+  | < #EscapeApos: "\\\'" >
+  | < #EscapeBslash: "\\\\" >
+  | < #EscapeSlash: "\\/" >
+  | < #EscapeBspace: "\\b" >
+  | < #EscapeFormf: "\\f" >
+  | < #EscapeNl: "\\n" >
+  | < #EscapeCr: "\\r" >
+  | < #EscapeTab: "\\t" >
+}
+
+<DEFAULT,IN_DBL_BRACE>
+TOKEN :
+{
+    <IDENTIFIER : <LETTER> (<LETTER> | <DIGIT> | <SPECIALCHARS>)*>
+}
+
+<DEFAULT,IN_DBL_BRACE>
+TOKEN :
+{
+    <VARIABLE : "$" <LETTER> (<LETTER> | <DIGIT> | "_")*>
+}
+
+<DEFAULT,IN_DBL_BRACE>
+SKIP:
+{
+    " "
+  | "\t"
+  | "\r"
+  | "\n"
+}
+
+<DEFAULT,IN_DBL_BRACE>
+SKIP:
+{
+    <"//" (~["\n"])* "\n">
+}
+
+<DEFAULT,IN_DBL_BRACE>
+SKIP:
+{
+    <"//" (~["\n","\r"])* ("\n"|"\r"|"\r\n")?>
+}
+
+<DEFAULT,IN_DBL_BRACE>
+SKIP:
+{
+    <"/*"> { pushState(); } : INSIDE_COMMENT
+}
+
+<INSIDE_COMMENT>
+SPECIAL_TOKEN:
+{
+    <"+"(" ")*(~["*"])*>
+}
+
+<INSIDE_COMMENT>
+SKIP:
+{
+    <"/*"> { pushState(); }
+}
+
+<INSIDE_COMMENT>
+SKIP:
+{
+    <"*/"> { popState("*/"); }
+  | <~[]>
+}