diff --git a/asterixdb/asterix-algebra/src/main/java/org/apache/asterix/optimizer/rules/PushLimitIntoPrimarySearchRule.java b/asterixdb/asterix-algebra/src/main/java/org/apache/asterix/optimizer/rules/PushLimitIntoPrimarySearchRule.java
index d95a952..525624b 100644
--- a/asterixdb/asterix-algebra/src/main/java/org/apache/asterix/optimizer/rules/PushLimitIntoPrimarySearchRule.java
+++ b/asterixdb/asterix-algebra/src/main/java/org/apache/asterix/optimizer/rules/PushLimitIntoPrimarySearchRule.java
@@ -117,7 +117,7 @@
             extractInlinableVariablesFromAssign(assignOp, selectedVariables, varAssignRhs);
             if (!varAssignRhs.isEmpty()) {
                 if (inlineVisitor == null) {
-                    inlineVisitor = new InlineVariablesRule.InlineVariablesVisitor(varAssignRhs);
+                    inlineVisitor = new InlineVariablesRule.InlineVariablesVisitor(varAssignRhs, null);
                     inlineVisitor.setContext(context);
                     inlineVisitor.setOperator(select);
                 }
diff --git a/asterixdb/asterix-app/src/test/resources/optimizerts/queries/inline-single-reference/inline-single-reference_1.sqlpp b/asterixdb/asterix-app/src/test/resources/optimizerts/queries/inline-single-reference/inline-single-reference_1.sqlpp
new file mode 100644
index 0000000..ceeb153
--- /dev/null
+++ b/asterixdb/asterix-app/src/test/resources/optimizerts/queries/inline-single-reference/inline-single-reference_1.sqlpp
@@ -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.
+ */
+/*
+* Description  : Test inline single reference.
+* Expected Res : Success
+* Date         : 01/31/2015
+*/
+
+drop  dataverse test if exists;
+create  dataverse test;
+
+use test;
+
+create type TT as closed {
+  id : integer
+};
+
+create  dataset t1(TT) primary key id;
+
+SELECT a.doc,
+       a.name,
+       CASE WHEN h.uname IS VALUED THEN h.uname ELSE NULL END AS uname
+FROM t1 a
+UNNEST a.history h
+WHERE h.ts >= "1999-03-02T08:04:57.750006+00:00";
+
diff --git a/asterixdb/asterix-app/src/test/resources/optimizerts/queries/inline-single-reference/inline-single-reference_2.sqlpp b/asterixdb/asterix-app/src/test/resources/optimizerts/queries/inline-single-reference/inline-single-reference_2.sqlpp
new file mode 100644
index 0000000..d5a6c80
--- /dev/null
+++ b/asterixdb/asterix-app/src/test/resources/optimizerts/queries/inline-single-reference/inline-single-reference_2.sqlpp
@@ -0,0 +1,39 @@
+/*
+ * 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.
+ */
+/*
+* Description  : Test inline single reference.
+* Expected Res : Success
+* Date         : 01/31/2015
+*/
+
+drop  dataverse test if exists;
+create  dataverse test;
+
+use test;
+
+create type TT as closed {
+  id : integer
+};
+
+create  dataset t1(TT) primary key id;
+
+SELECT a.doc,
+       a.name
+FROM t1 a
+WHERE a.new = 1;
\ No newline at end of file
diff --git a/asterixdb/asterix-app/src/test/resources/optimizerts/queries/inline-single-reference/inline-single-reference_3.sqlpp b/asterixdb/asterix-app/src/test/resources/optimizerts/queries/inline-single-reference/inline-single-reference_3.sqlpp
new file mode 100644
index 0000000..dcec0bc
--- /dev/null
+++ b/asterixdb/asterix-app/src/test/resources/optimizerts/queries/inline-single-reference/inline-single-reference_3.sqlpp
@@ -0,0 +1,39 @@
+/*
+ * 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.
+ */
+/*
+* Description  : Test inline single reference.
+* Expected Res : Success
+* Date         : 01/31/2015
+*/
+
+drop  dataverse test if exists;
+create  dataverse test;
+
+use test;
+
+create type TT as closed {
+  id : integer
+};
+
+create  dataset t1(TT) primary key id;
+
+SELECT a.doc,
+       a.name
+FROM t1 a
+ORDER BY a.id;
\ No newline at end of file
diff --git a/asterixdb/asterix-app/src/test/resources/optimizerts/queries/inline-single-reference/inline-single-reference_4.sqlpp b/asterixdb/asterix-app/src/test/resources/optimizerts/queries/inline-single-reference/inline-single-reference_4.sqlpp
new file mode 100644
index 0000000..25bba2b
--- /dev/null
+++ b/asterixdb/asterix-app/src/test/resources/optimizerts/queries/inline-single-reference/inline-single-reference_4.sqlpp
@@ -0,0 +1,41 @@
+/*
+ * 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.
+ */
+/*
+* Description  : Test inline single reference.
+* Expected Res : Success
+* Date         : 01/31/2015
+*/
+
+drop  dataverse test if exists;
+create  dataverse test;
+
+use test;
+
+create type TT as closed {
+  id : integer
+};
+
+create  dataset t1(TT) primary key id;
+create  dataset t2(TT) primary key id;
+
+SELECT a.doc,
+       b.name
+FROM t1 a, t2 b
+WHERE a.jn = b.jn
+ORDER BY a.id;
\ No newline at end of file
diff --git a/asterixdb/asterix-app/src/test/resources/optimizerts/results/inline-single-reference/inline-single-reference_1.plan b/asterixdb/asterix-app/src/test/resources/optimizerts/results/inline-single-reference/inline-single-reference_1.plan
new file mode 100644
index 0000000..3745304
--- /dev/null
+++ b/asterixdb/asterix-app/src/test/resources/optimizerts/results/inline-single-reference/inline-single-reference_1.plan
@@ -0,0 +1,12 @@
+-- DISTRIBUTE_RESULT  |PARTITIONED|
+  -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+    -- ASSIGN  |PARTITIONED|
+      -- STREAM_SELECT  |PARTITIONED|
+        -- ASSIGN  |PARTITIONED|
+          -- UNNEST  |PARTITIONED|
+            -- ASSIGN  |PARTITIONED|
+              -- STREAM_PROJECT  |PARTITIONED|
+                -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                  -- DATASOURCE_SCAN (test.t1)  |PARTITIONED|
+                    -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                      -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
diff --git a/asterixdb/asterix-app/src/test/resources/optimizerts/results/inline-single-reference/inline-single-reference_2.plan b/asterixdb/asterix-app/src/test/resources/optimizerts/results/inline-single-reference/inline-single-reference_2.plan
new file mode 100644
index 0000000..3c9b8ec
--- /dev/null
+++ b/asterixdb/asterix-app/src/test/resources/optimizerts/results/inline-single-reference/inline-single-reference_2.plan
@@ -0,0 +1,9 @@
+-- DISTRIBUTE_RESULT  |PARTITIONED|
+  -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+    -- ASSIGN  |PARTITIONED|
+      -- STREAM_SELECT  |PARTITIONED|
+        -- STREAM_PROJECT  |PARTITIONED|
+          -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+            -- DATASOURCE_SCAN (test.t1)  |PARTITIONED|
+              -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
diff --git a/asterixdb/asterix-app/src/test/resources/optimizerts/results/inline-single-reference/inline-single-reference_3.plan b/asterixdb/asterix-app/src/test/resources/optimizerts/results/inline-single-reference/inline-single-reference_3.plan
new file mode 100644
index 0000000..aa769d2
--- /dev/null
+++ b/asterixdb/asterix-app/src/test/resources/optimizerts/results/inline-single-reference/inline-single-reference_3.plan
@@ -0,0 +1,10 @@
+-- DISTRIBUTE_RESULT  |PARTITIONED|
+  -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+    -- ASSIGN  |PARTITIONED|
+      -- STREAM_PROJECT  |PARTITIONED|
+        -- SORT_MERGE_EXCHANGE [$$18(ASC) ]  |PARTITIONED|
+          -- STABLE_SORT [$$18(ASC)]  |PARTITIONED|
+            -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+              -- DATASOURCE_SCAN (test.t1)  |PARTITIONED|
+                -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                  -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
diff --git a/asterixdb/asterix-app/src/test/resources/optimizerts/results/inline-single-reference/inline-single-reference_4.plan b/asterixdb/asterix-app/src/test/resources/optimizerts/results/inline-single-reference/inline-single-reference_4.plan
new file mode 100644
index 0000000..30d22c2
--- /dev/null
+++ b/asterixdb/asterix-app/src/test/resources/optimizerts/results/inline-single-reference/inline-single-reference_4.plan
@@ -0,0 +1,23 @@
+-- DISTRIBUTE_RESULT  |PARTITIONED|
+  -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+    -- ASSIGN  |PARTITIONED|
+      -- STREAM_PROJECT  |PARTITIONED|
+        -- SORT_MERGE_EXCHANGE [$$33(ASC) ]  |PARTITIONED|
+          -- STABLE_SORT [$$33(ASC)]  |PARTITIONED|
+            -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+              -- STREAM_PROJECT  |PARTITIONED|
+                -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                  -- HYBRID_HASH_JOIN [$$35][$$36]  |PARTITIONED|
+                    -- HASH_PARTITION_EXCHANGE [$$35]  |PARTITIONED|
+                      -- ASSIGN  |PARTITIONED|
+                        -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                          -- DATASOURCE_SCAN (test.t1)  |PARTITIONED|
+                            -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                              -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
+                    -- HASH_PARTITION_EXCHANGE [$$36]  |PARTITIONED|
+                      -- ASSIGN  |PARTITIONED|
+                        -- STREAM_PROJECT  |PARTITIONED|
+                          -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                            -- DATASOURCE_SCAN (test.t2)  |PARTITIONED|
+                              -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                                -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
diff --git a/asterixdb/asterix-app/src/test/resources/optimizerts/results/inverted-index-join/ngram-jaccard-check_04.plan b/asterixdb/asterix-app/src/test/resources/optimizerts/results/inverted-index-join/ngram-jaccard-check_04.plan
index e06ae9f..243faab 100644
--- a/asterixdb/asterix-app/src/test/resources/optimizerts/results/inverted-index-join/ngram-jaccard-check_04.plan
+++ b/asterixdb/asterix-app/src/test/resources/optimizerts/results/inverted-index-join/ngram-jaccard-check_04.plan
@@ -5,9 +5,11 @@
         -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
           -- HYBRID_HASH_JOIN [$$61][$$49]  |PARTITIONED|
             -- HASH_PARTITION_EXCHANGE [$$61]  |PARTITIONED|
-              -- DATASOURCE_SCAN (test.DBLP)  |PARTITIONED|
+              -- ASSIGN  |PARTITIONED|
                 -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
-                  -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
+                  -- DATASOURCE_SCAN (test.DBLP)  |PARTITIONED|
+                    -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                      -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
             -- HASH_PARTITION_EXCHANGE [$$49]  |PARTITIONED|
               -- STREAM_SELECT  |PARTITIONED|
                 -- ASSIGN  |PARTITIONED|
diff --git a/asterixdb/asterix-app/src/test/resources/optimizerts/results/inverted-index-join/ngram-jaccard_04.plan b/asterixdb/asterix-app/src/test/resources/optimizerts/results/inverted-index-join/ngram-jaccard_04.plan
index a4041cd..2382014 100644
--- a/asterixdb/asterix-app/src/test/resources/optimizerts/results/inverted-index-join/ngram-jaccard_04.plan
+++ b/asterixdb/asterix-app/src/test/resources/optimizerts/results/inverted-index-join/ngram-jaccard_04.plan
@@ -5,9 +5,11 @@
         -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
           -- HYBRID_HASH_JOIN [$$61][$$48]  |PARTITIONED|
             -- HASH_PARTITION_EXCHANGE [$$61]  |PARTITIONED|
-              -- DATASOURCE_SCAN (test.DBLP)  |PARTITIONED|
+              -- ASSIGN  |PARTITIONED|
                 -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
-                  -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
+                  -- DATASOURCE_SCAN (test.DBLP)  |PARTITIONED|
+                    -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                      -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
             -- HASH_PARTITION_EXCHANGE [$$48]  |PARTITIONED|
               -- STREAM_SELECT  |PARTITIONED|
                 -- ASSIGN  |PARTITIONED|
diff --git a/asterixdb/asterix-app/src/test/resources/optimizerts/results/inverted-index-join/word-jaccard-check_04.plan b/asterixdb/asterix-app/src/test/resources/optimizerts/results/inverted-index-join/word-jaccard-check_04.plan
index c48868f..623f0c5 100644
--- a/asterixdb/asterix-app/src/test/resources/optimizerts/results/inverted-index-join/word-jaccard-check_04.plan
+++ b/asterixdb/asterix-app/src/test/resources/optimizerts/results/inverted-index-join/word-jaccard-check_04.plan
@@ -5,9 +5,11 @@
         -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
           -- HYBRID_HASH_JOIN [$$61][$$49]  |PARTITIONED|
             -- HASH_PARTITION_EXCHANGE [$$61]  |PARTITIONED|
-              -- DATASOURCE_SCAN (test.DBLP)  |PARTITIONED|
+              -- ASSIGN  |PARTITIONED|
                 -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
-                  -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
+                  -- DATASOURCE_SCAN (test.DBLP)  |PARTITIONED|
+                    -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                      -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
             -- HASH_PARTITION_EXCHANGE [$$49]  |PARTITIONED|
               -- STREAM_SELECT  |PARTITIONED|
                 -- ASSIGN  |PARTITIONED|
diff --git a/asterixdb/asterix-app/src/test/resources/optimizerts/results/inverted-index-join/word-jaccard_04.plan b/asterixdb/asterix-app/src/test/resources/optimizerts/results/inverted-index-join/word-jaccard_04.plan
index e56f7a6..2616a99 100644
--- a/asterixdb/asterix-app/src/test/resources/optimizerts/results/inverted-index-join/word-jaccard_04.plan
+++ b/asterixdb/asterix-app/src/test/resources/optimizerts/results/inverted-index-join/word-jaccard_04.plan
@@ -5,9 +5,11 @@
         -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
           -- HYBRID_HASH_JOIN [$$61][$$48]  |PARTITIONED|
             -- HASH_PARTITION_EXCHANGE [$$61]  |PARTITIONED|
-              -- DATASOURCE_SCAN (test.DBLP)  |PARTITIONED|
+              -- ASSIGN  |PARTITIONED|
                 -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
-                  -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
+                  -- DATASOURCE_SCAN (test.DBLP)  |PARTITIONED|
+                    -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                      -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
             -- HASH_PARTITION_EXCHANGE [$$48]  |PARTITIONED|
               -- STREAM_SELECT  |PARTITIONED|
                 -- ASSIGN  |PARTITIONED|
diff --git a/hyracks-fullstack/algebricks/algebricks-rewriter/src/main/java/org/apache/hyracks/algebricks/rewriter/rules/InlineSingleReferenceVariablesRule.java b/hyracks-fullstack/algebricks/algebricks-rewriter/src/main/java/org/apache/hyracks/algebricks/rewriter/rules/InlineSingleReferenceVariablesRule.java
index be169f4..77a97c8 100644
--- a/hyracks-fullstack/algebricks/algebricks-rewriter/src/main/java/org/apache/hyracks/algebricks/rewriter/rules/InlineSingleReferenceVariablesRule.java
+++ b/hyracks-fullstack/algebricks/algebricks-rewriter/src/main/java/org/apache/hyracks/algebricks/rewriter/rules/InlineSingleReferenceVariablesRule.java
@@ -19,13 +19,16 @@
 package org.apache.hyracks.algebricks.rewriter.rules;
 
 import java.util.ArrayList;
+import java.util.HashSet;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Set;
 
 import org.apache.hyracks.algebricks.common.exceptions.AlgebricksException;
 import org.apache.hyracks.algebricks.core.algebra.base.ILogicalOperator;
 import org.apache.hyracks.algebricks.core.algebra.base.IOptimizationContext;
+import org.apache.hyracks.algebricks.core.algebra.base.LogicalOperatorTag;
 import org.apache.hyracks.algebricks.core.algebra.base.LogicalVariable;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.visitors.VariableUtilities;
 
@@ -50,15 +53,18 @@
 public class InlineSingleReferenceVariablesRule extends InlineVariablesRule {
 
     // Maps from variable to a list of operators using that variable.
-    protected Map<LogicalVariable, List<ILogicalOperator>> usedVarsMap =
-            new LinkedHashMap<LogicalVariable, List<ILogicalOperator>>();
-    protected List<LogicalVariable> usedVars = new ArrayList<LogicalVariable>();
+    protected Map<LogicalVariable, List<ILogicalOperator>> usedVarsMap = new LinkedHashMap<>();
+    protected List<LogicalVariable> usedVars = new ArrayList<>();
+    protected Set<LogicalVariable> usedResultVars = new HashSet<>();
+    protected Set<LogicalVariable> docRefVars = new HashSet<>();
 
     @Override
     protected void prepare(IOptimizationContext context) {
         super.prepare(context);
         usedVarsMap.clear();
         usedVars.clear();
+        usedResultVars.clear();
+        docRefVars.clear();
     }
 
     @Override
@@ -71,6 +77,8 @@
                 if (!op.requiresVariableReferenceExpressions()) {
                     inlineVisitor.setOperator(op);
                     inlineVisitor.setTargetVariable(entry.getKey());
+                    inlineVisitor.setUsedResultVars(usedResultVars);
+                    inlineVisitor.setDocRefVars(docRefVars);
                     if (op.accept(inlineVisitor, inlineVisitor)) {
                         modified = true;
                     }
@@ -83,6 +91,14 @@
 
     @Override
     protected boolean performBottomUpAction(ILogicalOperator op) throws AlgebricksException {
+        if (op.getOperatorTag() == LogicalOperatorTag.DISTRIBUTE_RESULT) {
+            VariableUtilities.getUsedVariables(op, usedResultVars);
+        }
+        if (op.getOperatorTag() == LogicalOperatorTag.DATASOURCESCAN
+                || op.getOperatorTag() == LogicalOperatorTag.UNNEST_MAP) {
+            // TODO: We should find a way to exclude primary keys from the produced variables.
+            VariableUtilities.getProducedVariables(op, docRefVars);
+        }
         usedVars.clear();
         VariableUtilities.getUsedVariables(op, usedVars);
         for (LogicalVariable var : usedVars) {
diff --git a/hyracks-fullstack/algebricks/algebricks-rewriter/src/main/java/org/apache/hyracks/algebricks/rewriter/rules/InlineVariablesRule.java b/hyracks-fullstack/algebricks/algebricks-rewriter/src/main/java/org/apache/hyracks/algebricks/rewriter/rules/InlineVariablesRule.java
index 5970f4f..f344343 100644
--- a/hyracks-fullstack/algebricks/algebricks-rewriter/src/main/java/org/apache/hyracks/algebricks/rewriter/rules/InlineVariablesRule.java
+++ b/hyracks-fullstack/algebricks/algebricks-rewriter/src/main/java/org/apache/hyracks/algebricks/rewriter/rules/InlineVariablesRule.java
@@ -71,11 +71,14 @@
 
     // map of variables that could be replaced by their producing expression.
     // populated during the top-down sweep of the plan.
-    private Map<LogicalVariable, ILogicalExpression> varAssignRhs = new HashMap<>();
+    private final Map<LogicalVariable, ILogicalExpression> varAssignRhs = new HashMap<>();
+    // map of variables to the operator that produces the expression.
+    // populated during the top-down sweep of the plan.
+    private final Map<LogicalVariable, ILogicalOperator> varAssignOp = new HashMap<>();
     // visitor for replacing variable reference expressions with their originating expression.
-    protected InlineVariablesVisitor inlineVisitor = new InlineVariablesVisitor(varAssignRhs);
+    protected final InlineVariablesVisitor inlineVisitor = new InlineVariablesVisitor(varAssignRhs, varAssignOp);
     // set of FunctionIdentifiers that we should not inline.
-    protected Set<FunctionIdentifier> doNotInlineFuncs = new HashSet<>();
+    protected final Set<FunctionIdentifier> doNotInlineFuncs = new HashSet<>();
     // indicates whether the rule has been run
     private boolean hasRun = false;
     // set to prevent re-visiting a subtree from the other sides. Operators with multiple outputs are the ones that
@@ -112,6 +115,7 @@
 
     protected void prepare(IOptimizationContext context) {
         varAssignRhs.clear();
+        varAssignOp.clear();
         inlineVisitor.setContext(context);
         subTreesDone.clear();
         usedVariableCounter.clear();
@@ -160,6 +164,7 @@
                     }
                 }
                 varAssignRhs.put(variable, expr);
+                varAssignOp.put(variable, assignOp);
             }
         }
 
@@ -181,6 +186,7 @@
                 if (varMap != null && !varMap.isEmpty() && Collections.max(varMap.values()) > context
                         .getPhysicalOptimizationConfig().getMaxVariableOccurrencesForInlining()) {
                     varAssignRhs.remove(variable);
+                    varAssignOp.remove(variable);
                 }
             }
         }
@@ -198,6 +204,7 @@
                     Set<LogicalVariable> producedVars = new HashSet<>();
                     VariableUtilities.getProducedVariables(root.getValue(), producedVars);
                     varAssignRhs.keySet().removeAll(producedVars);
+                    varAssignOp.keySet().removeAll(producedVars);
                 }
             }
         }
@@ -208,6 +215,7 @@
             Set<LogicalVariable> rightLiveVars = new HashSet<>();
             VariableUtilities.getLiveVariables(op.getInputs().get(1).getValue(), rightLiveVars);
             varAssignRhs.keySet().removeAll(rightLiveVars);
+            varAssignOp.keySet().removeAll(rightLiveVars);
         }
 
         if (performBottomUpAction(op)) {
@@ -302,15 +310,21 @@
             implements ILogicalExpressionReferenceTransform {
 
         private final Map<LogicalVariable, ILogicalExpression> varAssignRhs;
+        private final Map<LogicalVariable, ILogicalOperator> varAssignOp;
         private final Set<LogicalVariable> liveVars = new HashSet<>();
         private final List<LogicalVariable> rhsUsedVars = new ArrayList<>();
         private ILogicalOperator op;
         private IOptimizationContext context;
         // If set, only replace this variable reference.
         private LogicalVariable targetVar;
+        private Set<LogicalVariable> usedResultVars = new HashSet<>();
+        private Set<LogicalVariable> docRefVars = new HashSet<>();
+        private List<LogicalVariable> opProducedVars = new ArrayList<>();
 
-        public InlineVariablesVisitor(Map<LogicalVariable, ILogicalExpression> varAssignRhs) {
+        public InlineVariablesVisitor(Map<LogicalVariable, ILogicalExpression> varAssignRhs,
+                Map<LogicalVariable, ILogicalOperator> varAssignOp) {
             this.varAssignRhs = varAssignRhs;
+            this.varAssignOp = varAssignOp;
         }
 
         public void setTargetVariable(LogicalVariable targetVar) {
@@ -326,6 +340,14 @@
             liveVars.clear();
         }
 
+        public void setUsedResultVars(Set<LogicalVariable> usedResultVars) {
+            this.usedResultVars = usedResultVars;
+        }
+
+        public void setDocRefVars(Set<LogicalVariable> docRefVars) {
+            this.docRefVars = docRefVars;
+        }
+
         @Override
         public Boolean visitWindowOperator(WindowOperator op, ILogicalExpressionReferenceTransform arg)
                 throws AlgebricksException {
@@ -369,6 +391,10 @@
             }
 
             ILogicalExpression rhs = varAssignRhs.get(var);
+            ILogicalOperator rhsOp = null;
+            if (varAssignOp != null) {
+                rhsOp = varAssignOp.get(var);
+            }
             if (rhs == null) {
                 // Variable was not produced by an assign.
                 return false;
@@ -384,11 +410,58 @@
                 if (!liveVars.contains(rhsUsedVar)) {
                     return false;
                 }
+                // Do not inline an expression that contains the doc variable (e.g. $$abc) if there is a “sensitive”
+                // operator in between this op and the op that produced the expression. A "sensitive" operator is one
+                // that would be more expensive if the size of the data flowing through it is bigger.
+                if (docRefVars.contains(rhsUsedVar) && opProducedVarsInResultVars(op)
+                        && !safeToInlineVariables(op, rhsOp)) {
+                    return false;
+                }
             }
 
             // Replace variable reference with a clone of the rhs expr.
             exprRef.setValue(rhs.cloneExpression());
             return true;
         }
+
+        private boolean opProducedVarsInResultVars(ILogicalOperator op) throws AlgebricksException {
+            opProducedVars.clear();
+            VariableUtilities.getProducedVariables(op, opProducedVars);
+            for (LogicalVariable pVar : opProducedVars) {
+                if (usedResultVars.contains(pVar)) {
+                    return true;
+                }
+            }
+            return false;
+        }
+
+        private boolean safeToInlineVariables(ILogicalOperator op, ILogicalOperator rhsOp) throws AlgebricksException {
+            ILogicalOperator currentOp = op;
+            while (currentOp != null) {
+                if (currentOp.getOperatorTag() == LogicalOperatorTag.DATASOURCESCAN
+                        || currentOp.getOperatorTag() == LogicalOperatorTag.UNNEST_MAP) {
+                    break;
+                }
+                if (rhsOp != null && currentOp == rhsOp) {
+                    break;
+
+                }
+                if (sensitiveOpForInlining(currentOp)) {
+                    return false;
+                }
+                currentOp = currentOp.getInputs().get(0).getValue();
+            }
+            return true;
+        }
+
+        private boolean sensitiveOpForInlining(ILogicalOperator op) {
+            if (op.getInputs().size() != 1) {
+                return true;
+            }
+            return switch (op.getOperatorTag()) {
+                case ORDER, UNNEST -> true;
+                default -> false;
+            };
+        }
     }
 }