ASTERIXDB-1081, ASTERIXDB-1086, ASTERIXDB-1246: proper multiple plan paths handling
- ASTERIXDB-1081: Fixed RemoveUnusedAssignAndAggregateRule to reflect multiple paths in the plan.
- ASTERIXDB-1086: Fixed IntroduceProjectsRule to reflect multiples paths in the plan.
- ASTERIXDB-1246: Fixed RemoveRedundantGroupByDecorVarsRule to remove duplicate/unnecessary
decor variables before IntroduceProjects rule fires.
Change-Id: I69e055572f024f28a857d4e64916b4806e63c083
Reviewed-on: https://asterix-gerrit.ics.uci.edu/1073
Sonar-Qube: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Tested-by: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Reviewed-by: Yingyi Bu <buyingyi@gmail.com>
Integration-Tests: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
diff --git a/asterixdb/asterix-algebra/src/main/java/org/apache/asterix/optimizer/base/RuleCollections.java b/asterixdb/asterix-algebra/src/main/java/org/apache/asterix/optimizer/base/RuleCollections.java
index e291dc1..cd8d747 100644
--- a/asterixdb/asterix-algebra/src/main/java/org/apache/asterix/optimizer/base/RuleCollections.java
+++ b/asterixdb/asterix-algebra/src/main/java/org/apache/asterix/optimizer/base/RuleCollections.java
@@ -115,7 +115,7 @@
import org.apache.hyracks.algebricks.rewriter.rules.PushUnnestDownThroughUnionRule;
import org.apache.hyracks.algebricks.rewriter.rules.ReinferAllTypesRule;
import org.apache.hyracks.algebricks.rewriter.rules.RemoveCartesianProductWithEmptyBranchRule;
-import org.apache.hyracks.algebricks.rewriter.rules.RemoveRedundantGroupByDecorVars;
+import org.apache.hyracks.algebricks.rewriter.rules.RemoveRedundantGroupByDecorVarsRule;
import org.apache.hyracks.algebricks.rewriter.rules.RemoveRedundantVariablesRule;
import org.apache.hyracks.algebricks.rewriter.rules.RemoveUnnecessarySortMergeExchange;
import org.apache.hyracks.algebricks.rewriter.rules.RemoveUnusedAssignAndAggregateRule;
@@ -265,7 +265,7 @@
consolidation.add(new IntroduceAggregateCombinerRule());
consolidation.add(new CountVarToCountOneRule());
consolidation.add(new RemoveUnusedAssignAndAggregateRule());
- consolidation.add(new RemoveRedundantGroupByDecorVars());
+ consolidation.add(new RemoveRedundantGroupByDecorVarsRule());
//PushUnnestDownUnion => RemoveRedundantListifyRule cause these rules are correlated
consolidation.add(new PushUnnestDownThroughUnionRule());
consolidation.add(new RemoveRedundantListifyRule());
diff --git a/asterixdb/asterix-app/src/test/resources/optimizerts/results/query-issue562.plan b/asterixdb/asterix-app/src/test/resources/optimizerts/results/query-issue562.plan
index 9087eeb..931ec7d 100644
--- a/asterixdb/asterix-app/src/test/resources/optimizerts/results/query-issue562.plan
+++ b/asterixdb/asterix-app/src/test/resources/optimizerts/results/query-issue562.plan
@@ -9,57 +9,53 @@
-- NESTED_TUPLE_SOURCE |LOCAL|
}
-- HASH_PARTITION_MERGE_EXCHANGE MERGE:[$$82(ASC)] HASH:[$$82] |PARTITIONED|
- -- SORT_GROUP_BY[$$58] |PARTITIONED|
+ -- SORT_GROUP_BY[$$11] |PARTITIONED|
{
-- AGGREGATE |LOCAL|
-- NESTED_TUPLE_SOURCE |LOCAL|
}
-- ONE_TO_ONE_EXCHANGE |PARTITIONED|
-- STREAM_PROJECT |PARTITIONED|
- -- ASSIGN |PARTITIONED|
+ -- STREAM_SELECT |PARTITIONED|
-- STREAM_PROJECT |PARTITIONED|
- -- STREAM_SELECT |PARTITIONED|
- -- STREAM_PROJECT |PARTITIONED|
- -- ONE_TO_ONE_EXCHANGE |PARTITIONED|
- -- PRE_CLUSTERED_GROUP_BY[$$79] |PARTITIONED|
+ -- ONE_TO_ONE_EXCHANGE |PARTITIONED|
+ -- PRE_CLUSTERED_GROUP_BY[$$79] |PARTITIONED|
+ {
+ -- AGGREGATE |LOCAL|
+ -- NESTED_TUPLE_SOURCE |LOCAL|
+ }
+ -- HASH_PARTITION_MERGE_EXCHANGE MERGE:[$$79(ASC)] HASH:[$$79] |PARTITIONED|
+ -- PRE_CLUSTERED_GROUP_BY[$$75] |PARTITIONED|
{
-- AGGREGATE |LOCAL|
- -- NESTED_TUPLE_SOURCE |LOCAL|
+ -- STREAM_SELECT |LOCAL|
+ -- NESTED_TUPLE_SOURCE |LOCAL|
}
- -- HASH_PARTITION_MERGE_EXCHANGE MERGE:[$$79(ASC)] HASH:[$$79] |PARTITIONED|
- -- PRE_CLUSTERED_GROUP_BY[$$75] |PARTITIONED|
- {
- -- AGGREGATE |LOCAL|
- -- STREAM_SELECT |LOCAL|
- -- NESTED_TUPLE_SOURCE |LOCAL|
- }
+ -- ONE_TO_ONE_EXCHANGE |PARTITIONED|
+ -- STABLE_SORT [$$75(ASC)] |PARTITIONED|
-- ONE_TO_ONE_EXCHANGE |PARTITIONED|
- -- STABLE_SORT [$$75(ASC)] |PARTITIONED|
+ -- STREAM_PROJECT |PARTITIONED|
-- ONE_TO_ONE_EXCHANGE |PARTITIONED|
- -- STREAM_PROJECT |PARTITIONED|
- -- ONE_TO_ONE_EXCHANGE |PARTITIONED|
- -- HYBRID_HASH_JOIN [$$62][$$70] |PARTITIONED|
- -- HASH_PARTITION_EXCHANGE [$$62] |PARTITIONED|
- -- STREAM_PROJECT |PARTITIONED|
- -- ASSIGN |PARTITIONED|
- -- STREAM_PROJECT |PARTITIONED|
- -- ONE_TO_ONE_EXCHANGE |PARTITIONED|
- -- HYBRID_HASH_JOIN [$$65][$$11] |PARTITIONED|
- -- HASH_PARTITION_EXCHANGE [$$65] |PARTITIONED|
- -- UNNEST |UNPARTITIONED|
- -- EMPTY_TUPLE_SOURCE |UNPARTITIONED|
- -- HASH_PARTITION_EXCHANGE [$$11] |PARTITIONED|
- -- ASSIGN |PARTITIONED|
- -- STREAM_PROJECT |PARTITIONED|
- -- ASSIGN |PARTITIONED|
- -- ONE_TO_ONE_EXCHANGE |PARTITIONED|
- -- DATASOURCE_SCAN |PARTITIONED|
- -- ONE_TO_ONE_EXCHANGE |PARTITIONED|
- -- EMPTY_TUPLE_SOURCE |PARTITIONED|
- -- HASH_PARTITION_EXCHANGE [$$70] |PARTITIONED|
- -- ASSIGN |PARTITIONED|
- -- STREAM_PROJECT |PARTITIONED|
+ -- HYBRID_HASH_JOIN [$$62][$$70] |PARTITIONED|
+ -- HASH_PARTITION_EXCHANGE [$$62] |PARTITIONED|
+ -- ASSIGN |PARTITIONED|
+ -- STREAM_PROJECT |PARTITIONED|
+ -- ONE_TO_ONE_EXCHANGE |PARTITIONED|
+ -- HYBRID_HASH_JOIN [$$65][$$11] |PARTITIONED|
+ -- HASH_PARTITION_EXCHANGE [$$65] |PARTITIONED|
+ -- UNNEST |UNPARTITIONED|
+ -- EMPTY_TUPLE_SOURCE |UNPARTITIONED|
+ -- HASH_PARTITION_EXCHANGE [$$11] |PARTITIONED|
+ -- STREAM_PROJECT |PARTITIONED|
+ -- ASSIGN |PARTITIONED|
+ -- ONE_TO_ONE_EXCHANGE |PARTITIONED|
+ -- DATASOURCE_SCAN |PARTITIONED|
+ -- ONE_TO_ONE_EXCHANGE |PARTITIONED|
+ -- EMPTY_TUPLE_SOURCE |PARTITIONED|
+ -- HASH_PARTITION_EXCHANGE [$$70] |PARTITIONED|
+ -- ASSIGN |PARTITIONED|
+ -- STREAM_PROJECT |PARTITIONED|
+ -- ONE_TO_ONE_EXCHANGE |PARTITIONED|
+ -- DATASOURCE_SCAN |PARTITIONED|
-- ONE_TO_ONE_EXCHANGE |PARTITIONED|
- -- DATASOURCE_SCAN |PARTITIONED|
- -- ONE_TO_ONE_EXCHANGE |PARTITIONED|
- -- EMPTY_TUPLE_SOURCE |PARTITIONED|
+ -- EMPTY_TUPLE_SOURCE |PARTITIONED|
diff --git a/asterixdb/asterix-app/src/test/resources/optimizerts/results/subquery/exists.plan b/asterixdb/asterix-app/src/test/resources/optimizerts/results/subquery/exists.plan
index fcb9d0d..a379cb8 100644
--- a/asterixdb/asterix-app/src/test/resources/optimizerts/results/subquery/exists.plan
+++ b/asterixdb/asterix-app/src/test/resources/optimizerts/results/subquery/exists.plan
@@ -3,12 +3,12 @@
-- STREAM_PROJECT |PARTITIONED|
-- ASSIGN |PARTITIONED|
-- SORT_MERGE_EXCHANGE [$$31(ASC) ] |PARTITIONED|
- -- PRE_CLUSTERED_GROUP_BY[$$105] |PARTITIONED|
+ -- PRE_CLUSTERED_GROUP_BY[$$104] |PARTITIONED|
{
-- AGGREGATE |LOCAL|
-- NESTED_TUPLE_SOURCE |LOCAL|
}
- -- HASH_PARTITION_MERGE_EXCHANGE MERGE:[$$105(ASC)] HASH:[$$105] |PARTITIONED|
+ -- HASH_PARTITION_MERGE_EXCHANGE MERGE:[$$104(ASC)] HASH:[$$104] |PARTITIONED|
-- SORT_GROUP_BY[$$81] |PARTITIONED|
{
-- AGGREGATE |LOCAL|
@@ -21,12 +21,12 @@
-- STREAM_SELECT |PARTITIONED|
-- STREAM_PROJECT |PARTITIONED|
-- ONE_TO_ONE_EXCHANGE |PARTITIONED|
- -- PRE_CLUSTERED_GROUP_BY[$$102] |PARTITIONED|
+ -- PRE_CLUSTERED_GROUP_BY[$$101] |PARTITIONED|
{
-- AGGREGATE |LOCAL|
-- NESTED_TUPLE_SOURCE |LOCAL|
}
- -- HASH_PARTITION_MERGE_EXCHANGE MERGE:[$$102(ASC)] HASH:[$$102] |PARTITIONED|
+ -- HASH_PARTITION_MERGE_EXCHANGE MERGE:[$$101(ASC)] HASH:[$$101] |PARTITIONED|
-- PRE_CLUSTERED_GROUP_BY[$$95] |PARTITIONED|
{
-- AGGREGATE |LOCAL|
@@ -46,13 +46,12 @@
-- NESTED_LOOP |PARTITIONED|
-- ONE_TO_ONE_EXCHANGE |PARTITIONED|
-- ASSIGN |PARTITIONED|
- -- ASSIGN |PARTITIONED|
- -- STREAM_PROJECT |PARTITIONED|
- -- ASSIGN |PARTITIONED|
- -- ONE_TO_ONE_EXCHANGE |PARTITIONED|
- -- DATASOURCE_SCAN |PARTITIONED|
- -- ONE_TO_ONE_EXCHANGE |PARTITIONED|
- -- EMPTY_TUPLE_SOURCE |PARTITIONED|
+ -- STREAM_PROJECT |PARTITIONED|
+ -- ASSIGN |PARTITIONED|
+ -- ONE_TO_ONE_EXCHANGE |PARTITIONED|
+ -- DATASOURCE_SCAN |PARTITIONED|
+ -- ONE_TO_ONE_EXCHANGE |PARTITIONED|
+ -- EMPTY_TUPLE_SOURCE |PARTITIONED|
-- BROADCAST_EXCHANGE |PARTITIONED|
-- STREAM_PROJECT |UNPARTITIONED|
-- ASSIGN |UNPARTITIONED|
diff --git a/asterixdb/asterix-app/src/test/resources/optimizerts/results/subquery/not_exists.plan b/asterixdb/asterix-app/src/test/resources/optimizerts/results/subquery/not_exists.plan
index 2ef9a24..bc68200 100644
--- a/asterixdb/asterix-app/src/test/resources/optimizerts/results/subquery/not_exists.plan
+++ b/asterixdb/asterix-app/src/test/resources/optimizerts/results/subquery/not_exists.plan
@@ -3,12 +3,12 @@
-- STREAM_PROJECT |PARTITIONED|
-- ASSIGN |PARTITIONED|
-- SORT_MERGE_EXCHANGE [$$31(ASC) ] |PARTITIONED|
- -- PRE_CLUSTERED_GROUP_BY[$$106] |PARTITIONED|
+ -- PRE_CLUSTERED_GROUP_BY[$$105] |PARTITIONED|
{
-- AGGREGATE |LOCAL|
-- NESTED_TUPLE_SOURCE |LOCAL|
}
- -- HASH_PARTITION_MERGE_EXCHANGE MERGE:[$$106(ASC)] HASH:[$$106] |PARTITIONED|
+ -- HASH_PARTITION_MERGE_EXCHANGE MERGE:[$$105(ASC)] HASH:[$$105] |PARTITIONED|
-- SORT_GROUP_BY[$$82] |PARTITIONED|
{
-- AGGREGATE |LOCAL|
@@ -21,12 +21,12 @@
-- STREAM_SELECT |PARTITIONED|
-- STREAM_PROJECT |PARTITIONED|
-- ONE_TO_ONE_EXCHANGE |PARTITIONED|
- -- PRE_CLUSTERED_GROUP_BY[$$103] |PARTITIONED|
+ -- PRE_CLUSTERED_GROUP_BY[$$102] |PARTITIONED|
{
-- AGGREGATE |LOCAL|
-- NESTED_TUPLE_SOURCE |LOCAL|
}
- -- HASH_PARTITION_MERGE_EXCHANGE MERGE:[$$103(ASC)] HASH:[$$103] |PARTITIONED|
+ -- HASH_PARTITION_MERGE_EXCHANGE MERGE:[$$102(ASC)] HASH:[$$102] |PARTITIONED|
-- PRE_CLUSTERED_GROUP_BY[$$96] |PARTITIONED|
{
-- AGGREGATE |LOCAL|
@@ -46,13 +46,12 @@
-- NESTED_LOOP |PARTITIONED|
-- ONE_TO_ONE_EXCHANGE |PARTITIONED|
-- ASSIGN |PARTITIONED|
- -- ASSIGN |PARTITIONED|
- -- STREAM_PROJECT |PARTITIONED|
- -- ASSIGN |PARTITIONED|
- -- ONE_TO_ONE_EXCHANGE |PARTITIONED|
- -- DATASOURCE_SCAN |PARTITIONED|
- -- ONE_TO_ONE_EXCHANGE |PARTITIONED|
- -- EMPTY_TUPLE_SOURCE |PARTITIONED|
+ -- STREAM_PROJECT |PARTITIONED|
+ -- ASSIGN |PARTITIONED|
+ -- ONE_TO_ONE_EXCHANGE |PARTITIONED|
+ -- DATASOURCE_SCAN |PARTITIONED|
+ -- ONE_TO_ONE_EXCHANGE |PARTITIONED|
+ -- EMPTY_TUPLE_SOURCE |PARTITIONED|
-- BROADCAST_EXCHANGE |PARTITIONED|
-- STREAM_PROJECT |UNPARTITIONED|
-- ASSIGN |UNPARTITIONED|
diff --git a/hyracks-fullstack/algebricks/algebricks-rewriter/src/main/java/org/apache/hyracks/algebricks/rewriter/rules/IntroduceProjectsRule.java b/hyracks-fullstack/algebricks/algebricks-rewriter/src/main/java/org/apache/hyracks/algebricks/rewriter/rules/IntroduceProjectsRule.java
index c670b6b..d17e021 100644
--- a/hyracks-fullstack/algebricks/algebricks-rewriter/src/main/java/org/apache/hyracks/algebricks/rewriter/rules/IntroduceProjectsRule.java
+++ b/hyracks-fullstack/algebricks/algebricks-rewriter/src/main/java/org/apache/hyracks/algebricks/rewriter/rules/IntroduceProjectsRule.java
@@ -20,13 +20,14 @@
import java.util.ArrayList;
import java.util.Collections;
+import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
+import java.util.Map;
import java.util.Set;
import org.apache.commons.lang3.mutable.Mutable;
import org.apache.commons.lang3.mutable.MutableObject;
-
import org.apache.hyracks.algebricks.common.exceptions.AlgebricksException;
import org.apache.hyracks.algebricks.common.utils.Triple;
import org.apache.hyracks.algebricks.core.algebra.base.ILogicalOperator;
@@ -53,6 +54,8 @@
private final Set<LogicalVariable> producedVars = new HashSet<>();
private final List<LogicalVariable> projectVars = new ArrayList<>();
protected boolean hasRun = false;
+ // Keep track of used variables after the current operator, including used variables in itself.
+ private final Map<AbstractLogicalOperator, HashSet<LogicalVariable>> allUsedVarsAfterOpMap = new HashMap<>();
@Override
public boolean rewritePost(Mutable<ILogicalOperator> opRef, IOptimizationContext context) {
@@ -60,14 +63,48 @@
}
@Override
- public boolean rewritePre(Mutable<ILogicalOperator> opRef, IOptimizationContext context) throws AlgebricksException {
+ public boolean rewritePre(Mutable<ILogicalOperator> opRef, IOptimizationContext context)
+ throws AlgebricksException {
if (hasRun) {
return false;
}
hasRun = true;
+
+ // Collect all used variables after each operator, including the used variables in itself in the plan.
+ // This is necessary since introduceProjects() may generate a wrong project if it doesn't have the information
+ // for all paths in the plan in case there are two or more branches since it can only deal one path at a time.
+ // So, a variable used in one path might be removed while the method traverses another path.
+ Set<LogicalVariable> parentUsedVars = new HashSet<>();
+ collectUsedVars(opRef, parentUsedVars);
+
+ // Introduce projects
return introduceProjects(null, -1, opRef, Collections.<LogicalVariable> emptySet(), context);
}
+ /**
+ * Collect all used variables after each operator, including the used variables in itself in the plan.
+ * Collecting information in a separate method is required since there can be multiple paths in the plan
+ * and introduceProjects() method can deal with only one path at a time during conducting depth-first-search.
+ */
+ protected void collectUsedVars(Mutable<ILogicalOperator> opRef, Set<LogicalVariable> parentUsedVars)
+ throws AlgebricksException {
+ AbstractLogicalOperator op = (AbstractLogicalOperator) opRef.getValue();
+ HashSet<LogicalVariable> usedVarsPerOp = new HashSet<>();
+ VariableUtilities.getUsedVariables(op, usedVarsPerOp);
+ usedVarsPerOp.addAll(parentUsedVars);
+
+ if (allUsedVarsAfterOpMap.get(op) == null) {
+ allUsedVarsAfterOpMap.put(op, usedVarsPerOp);
+ } else {
+ allUsedVarsAfterOpMap.get(op).addAll(usedVarsPerOp);
+ }
+
+ for (Mutable<ILogicalOperator> inputOpRef : op.getInputs()) {
+ collectUsedVars(inputOpRef, usedVarsPerOp);
+ }
+
+ }
+
protected boolean introduceProjects(AbstractLogicalOperator parentOp, int parentInputIndex,
Mutable<ILogicalOperator> opRef, Set<LogicalVariable> parentUsedVars, IOptimizationContext context)
throws AlgebricksException {
@@ -78,10 +115,16 @@
VariableUtilities.getUsedVariables(op, usedVars);
// In the top-down pass, maintain a set of variables that are used in op and all its parents.
+ // This is a necessary step for the newly created project operator during this optimization,
+ // since we already have all information from collectUsedVars() method for the other operators.
HashSet<LogicalVariable> parentsUsedVars = new HashSet<>();
parentsUsedVars.addAll(parentUsedVars);
parentsUsedVars.addAll(usedVars);
+ if (allUsedVarsAfterOpMap.get(op) != null) {
+ parentsUsedVars.addAll(allUsedVarsAfterOpMap.get(op));
+ }
+
// Descend into children.
for (int i = 0; i < op.getInputs().size(); i++) {
Mutable<ILogicalOperator> inputOpRef = op.getInputs().get(i);
diff --git a/hyracks-fullstack/algebricks/algebricks-rewriter/src/main/java/org/apache/hyracks/algebricks/rewriter/rules/RemoveRedundantGroupByDecorVars.java b/hyracks-fullstack/algebricks/algebricks-rewriter/src/main/java/org/apache/hyracks/algebricks/rewriter/rules/RemoveRedundantGroupByDecorVars.java
deleted file mode 100644
index ebdc88a..0000000
--- a/hyracks-fullstack/algebricks/algebricks-rewriter/src/main/java/org/apache/hyracks/algebricks/rewriter/rules/RemoveRedundantGroupByDecorVars.java
+++ /dev/null
@@ -1,85 +0,0 @@
-/*
- * 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.hyracks.algebricks.rewriter.rules;
-
-import java.util.HashSet;
-import java.util.Iterator;
-import java.util.Set;
-
-import org.apache.commons.lang3.mutable.Mutable;
-
-import org.apache.hyracks.algebricks.common.exceptions.AlgebricksException;
-import org.apache.hyracks.algebricks.common.utils.Pair;
-import org.apache.hyracks.algebricks.core.algebra.base.ILogicalExpression;
-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.LogicalExpressionTag;
-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.expressions.VariableReferenceExpression;
-import org.apache.hyracks.algebricks.core.algebra.operators.logical.AbstractLogicalOperator;
-import org.apache.hyracks.algebricks.core.algebra.operators.logical.GroupByOperator;
-import org.apache.hyracks.algebricks.core.rewriter.base.IAlgebraicRewriteRule;
-
-/**
- * Removes duplicate variables from a group-by operator's decor list.
- */
-public class RemoveRedundantGroupByDecorVars implements IAlgebraicRewriteRule {
-
- private final Set<LogicalVariable> vars = new HashSet<LogicalVariable>();
-
- @Override
- public boolean rewritePost(Mutable<ILogicalOperator> opRef, IOptimizationContext context) {
- AbstractLogicalOperator op = (AbstractLogicalOperator) opRef.getValue();
- if (op.getOperatorTag() != LogicalOperatorTag.GROUP) {
- return false;
- }
- if (context.checkIfInDontApplySet(this, op)) {
- return false;
- }
- vars.clear();
-
- boolean modified = false;
- GroupByOperator groupOp = (GroupByOperator) op;
- Iterator<Pair<LogicalVariable, Mutable<ILogicalExpression>>> iter = groupOp.getDecorList().iterator();
- while (iter.hasNext()) {
- Pair<LogicalVariable, Mutable<ILogicalExpression>> decor = iter.next();
- if (decor.first != null || decor.second.getValue().getExpressionTag() != LogicalExpressionTag.VARIABLE) {
- continue;
- }
- VariableReferenceExpression varRefExpr = (VariableReferenceExpression) decor.second.getValue();
- LogicalVariable var = varRefExpr.getVariableReference();
- if (vars.contains(var)) {
- iter.remove();
- modified = true;
- } else {
- vars.add(var);
- }
- }
- if (modified) {
- context.addToDontApplySet(this, op);
- }
- return modified;
- }
-
- @Override
- public boolean rewritePre(Mutable<ILogicalOperator> opRef, IOptimizationContext context) throws AlgebricksException {
- return false;
- }
-}
diff --git a/hyracks-fullstack/algebricks/algebricks-rewriter/src/main/java/org/apache/hyracks/algebricks/rewriter/rules/RemoveRedundantGroupByDecorVarsRule.java b/hyracks-fullstack/algebricks/algebricks-rewriter/src/main/java/org/apache/hyracks/algebricks/rewriter/rules/RemoveRedundantGroupByDecorVarsRule.java
new file mode 100644
index 0000000..b9ad011
--- /dev/null
+++ b/hyracks-fullstack/algebricks/algebricks-rewriter/src/main/java/org/apache/hyracks/algebricks/rewriter/rules/RemoveRedundantGroupByDecorVarsRule.java
@@ -0,0 +1,156 @@
+/*
+ * 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.hyracks.algebricks.rewriter.rules;
+
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Set;
+
+import org.apache.commons.lang3.mutable.Mutable;
+import org.apache.hyracks.algebricks.common.exceptions.AlgebricksException;
+import org.apache.hyracks.algebricks.common.utils.Pair;
+import org.apache.hyracks.algebricks.core.algebra.base.ILogicalExpression;
+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.LogicalExpressionTag;
+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.expressions.VariableReferenceExpression;
+import org.apache.hyracks.algebricks.core.algebra.operators.logical.AbstractLogicalOperator;
+import org.apache.hyracks.algebricks.core.algebra.operators.logical.GroupByOperator;
+import org.apache.hyracks.algebricks.core.algebra.operators.logical.visitors.VariableUtilities;
+import org.apache.hyracks.algebricks.core.rewriter.base.IAlgebraicRewriteRule;
+
+/**
+ * Removes duplicate and/or unnecessary variables from a group-by operator's decor list.
+ */
+public class RemoveRedundantGroupByDecorVarsRule implements IAlgebraicRewriteRule {
+
+ private Set<LogicalVariable> usedVars = new HashSet<>();
+
+ @Override
+ public boolean rewritePre(Mutable<ILogicalOperator> opRef, IOptimizationContext context)
+ throws AlgebricksException {
+ AbstractLogicalOperator op = (AbstractLogicalOperator) opRef.getValue();
+ // Begin from the root operator to collect used variables after a possible group-by operator.
+ if (op.getOperatorTag() != LogicalOperatorTag.DISTRIBUTE_RESULT
+ && op.getOperatorTag() != LogicalOperatorTag.SINK) {
+ return false;
+ }
+ if (context.checkIfInDontApplySet(this, op)) {
+ return false;
+ }
+ usedVars.clear();
+ boolean planTransformed = checkAndApplyTheRule(opRef, context);
+
+ return planTransformed;
+ }
+
+ /**
+ * Collect used variables in each operator in the plan until the optimizer sees a GroupBy operator.
+ * It first removes duplicated variables in the decor list.
+ * Then, it eliminates useless variables in the decor list that are not going to be used
+ * after the given groupBy operator.
+ */
+ protected boolean checkAndApplyTheRule(Mutable<ILogicalOperator> opRef, IOptimizationContext context)
+ throws AlgebricksException {
+ AbstractLogicalOperator op = (AbstractLogicalOperator) opRef.getValue();
+ Set<LogicalVariable> usedVarsFromThisOp = new HashSet<>();
+ Set<LogicalVariable> collectedUsedVarsBeforeThisOpFromRoot = new HashSet<>();
+ boolean redundantVarsRemoved = false;
+ boolean uselessVarsRemoved = false;
+
+ // Found Group-By operator?
+ if (op.getOperatorTag() == LogicalOperatorTag.GROUP) {
+ GroupByOperator groupByOp = (GroupByOperator) op;
+ Set<LogicalVariable> decorVars = new HashSet<>();
+
+ // First, get rid of duplicated variables from a group-by operator's decor list.
+ Iterator<Pair<LogicalVariable, Mutable<ILogicalExpression>>> iter = groupByOp.getDecorList().iterator();
+ while (iter.hasNext()) {
+ Pair<LogicalVariable, Mutable<ILogicalExpression>> decor = iter.next();
+ if (decor.first != null
+ || decor.second.getValue().getExpressionTag() != LogicalExpressionTag.VARIABLE) {
+ continue;
+ }
+ VariableReferenceExpression varRefExpr = (VariableReferenceExpression) decor.second.getValue();
+ LogicalVariable var = varRefExpr.getVariableReference();
+ if (decorVars.contains(var)) {
+ iter.remove();
+ redundantVarsRemoved = true;
+ } else {
+ decorVars.add(var);
+ }
+ }
+
+ // Next, get rid of useless decor variables in the GROUP-BY operator.
+ List<Pair<LogicalVariable, Mutable<ILogicalExpression>>> newDecorList = new ArrayList<>();
+ for (Pair<LogicalVariable, Mutable<ILogicalExpression>> p : groupByOp.getDecorList()) {
+ LogicalVariable decorVar = GroupByOperator.getDecorVariable(p);
+ // If a variable in the decor list will not be used after this operator, then it needs to be removed.
+ if (!usedVars.contains(decorVar)) {
+ uselessVarsRemoved = true;
+ } else {
+ // Maintain the variable since it will be used.
+ newDecorList.add(p);
+ }
+ }
+
+ // If we have identified useless decor variables,
+ // then the decor list needs to be reset without those variables.
+ if (uselessVarsRemoved) {
+ groupByOp.getDecorList().clear();
+ groupByOp.getDecorList().addAll(newDecorList);
+ }
+
+ // If the plan transformation is successful, we don't need to traverse the plan any more,
+ // since if there are more GROUP-BY operators, the next trigger on this plan will find them.
+ if (redundantVarsRemoved || uselessVarsRemoved) {
+ context.computeAndSetTypeEnvironmentForOperator(groupByOp);
+ context.addToDontApplySet(this, op);
+ return redundantVarsRemoved || uselessVarsRemoved;
+ }
+ }
+
+ // Either we have found a GroupBy operator but no removal is happened or
+ // there we haven't found a GroupBy operator yet. Thus, we add used variables for this operator
+ // and keep traversing the plan.
+ VariableUtilities.getUsedVariables(op, usedVarsFromThisOp);
+ collectedUsedVarsBeforeThisOpFromRoot.addAll(usedVars);
+ usedVars.addAll(usedVarsFromThisOp);
+
+ // Recursively check the plan and try to optimize it.
+ for (int i = 0; i < op.getInputs().size(); i++) {
+ boolean groupByChanged = checkAndApplyTheRule(op.getInputs().get(i), context);
+ if (groupByChanged) {
+ return true;
+ }
+ }
+
+ // This rule can't be applied to this operator or its descendants.
+ // Thus, remove the effects of this operator so that the depth-first-search can return to the parent.
+ usedVars.clear();
+ usedVars.addAll(collectedUsedVarsBeforeThisOpFromRoot);
+
+ return false;
+ }
+
+}
diff --git a/hyracks-fullstack/algebricks/algebricks-rewriter/src/main/java/org/apache/hyracks/algebricks/rewriter/rules/RemoveUnusedAssignAndAggregateRule.java b/hyracks-fullstack/algebricks/algebricks-rewriter/src/main/java/org/apache/hyracks/algebricks/rewriter/rules/RemoveUnusedAssignAndAggregateRule.java
index 90ab975..55831f0 100644
--- a/hyracks-fullstack/algebricks/algebricks-rewriter/src/main/java/org/apache/hyracks/algebricks/rewriter/rules/RemoveUnusedAssignAndAggregateRule.java
+++ b/hyracks-fullstack/algebricks/algebricks-rewriter/src/main/java/org/apache/hyracks/algebricks/rewriter/rules/RemoveUnusedAssignAndAggregateRule.java
@@ -21,8 +21,9 @@
import java.util.ArrayList;
import java.util.HashSet;
import java.util.Iterator;
-import java.util.LinkedList;
+import java.util.LinkedHashMap;
import java.util.List;
+import java.util.Map;
import java.util.Set;
import org.apache.commons.lang3.mutable.Mutable;
@@ -52,47 +53,120 @@
*/
public class RemoveUnusedAssignAndAggregateRule implements IAlgebraicRewriteRule {
+ // Keep the variables that are produced by ASSIGN, UNNEST, AGGREGATE, UNION,
+ // and GROUP operators.
+ private Map<Mutable<ILogicalOperator>, Set<LogicalVariable>> assignedVarMap = new LinkedHashMap<>();
+ private Set<LogicalVariable> assignedVarSet = new HashSet<>();
+
+ // Keep the variables that are used after ASSIGN, UNNEST, AGGREGATE, UNION,
+ // and GROUP operators.
+ private Map<Mutable<ILogicalOperator>, Set<LogicalVariable>> accumulatedUsedVarFromRootMap = new LinkedHashMap<>();
+
+ private boolean isTransformed = false;
+
+ // Keep the variable-mapping of a UNION operator.
+ // This is required to keep the variables of the left or right branch of the UNION operator
+ // if the output variable of the UNION operator is survived.
+ private Set<LogicalVariable> survivedUnionSourceVarSet = new HashSet<>();
+
@Override
public boolean rewritePost(Mutable<ILogicalOperator> opRef, IOptimizationContext context) {
return false;
}
@Override
- public boolean rewritePre(Mutable<ILogicalOperator> opRef, IOptimizationContext context) throws AlgebricksException {
+ public boolean rewritePre(Mutable<ILogicalOperator> opRef, IOptimizationContext context)
+ throws AlgebricksException {
if (context.checkIfInDontApplySet(this, opRef.getValue())) {
return false;
}
- Set<LogicalVariable> toRemove = new HashSet<LogicalVariable>();
- collectUnusedAssignedVars((AbstractLogicalOperator) opRef.getValue(), toRemove, true, context);
- boolean smthToRemove = !toRemove.isEmpty();
- if (smthToRemove) {
- removeUnusedAssigns(opRef, toRemove, context);
+
+ clear();
+ Set<LogicalVariable> accumulatedUsedVarFromRootSet = new HashSet<>();
+ collectUnusedAssignedVars(opRef, accumulatedUsedVarFromRootSet, true, context);
+
+ // If there are ASSIGN, UNNEST, AGGREGATE, UNION, and GROUP operators in the plan,
+ // we try to remove these operators if the produced variables from these
+ // operators are not used.
+ if (!assignedVarMap.isEmpty()) {
+ removeUnusedAssigns(opRef, context);
}
- return !toRemove.isEmpty();
+
+ return isTransformed;
}
- private void removeUnusedAssigns(Mutable<ILogicalOperator> opRef, Set<LogicalVariable> toRemove,
- IOptimizationContext context) throws AlgebricksException {
+ /**
+ * Collect the information from the given operator and removes assigned
+ * variables if they are used afterwards.
+ */
+ private Set<LogicalVariable> removeAssignVarFromConsideration(Mutable<ILogicalOperator> opRef) {
+ Set<LogicalVariable> assignVarsSetForThisOp = null;
+ Set<LogicalVariable> usedVarsSetForThisOp = null;
+
+ if (accumulatedUsedVarFromRootMap.containsKey(opRef)) {
+ usedVarsSetForThisOp = accumulatedUsedVarFromRootMap.get(opRef);
+ }
+
+ if (assignedVarMap.containsKey(opRef)) {
+ assignVarsSetForThisOp = assignedVarMap.get(opRef);
+ }
+
+ if (assignVarsSetForThisOp != null && !assignVarsSetForThisOp.isEmpty()) {
+ Iterator<LogicalVariable> varIter = assignVarsSetForThisOp.iterator();
+ while (varIter.hasNext()) {
+ LogicalVariable v = varIter.next();
+ if ((usedVarsSetForThisOp != null && usedVarsSetForThisOp.contains(v))
+ || survivedUnionSourceVarSet.contains(v)) {
+ varIter.remove();
+ }
+ }
+ }
+
+ // The source variables of the UNIONALL operator should be survived
+ // since we are sure that the output of UNIONALL operator is used
+ // afterwards.
+ if (opRef.getValue().getOperatorTag() == LogicalOperatorTag.UNIONALL) {
+ Iterator<Triple<LogicalVariable, LogicalVariable, LogicalVariable>> iter = ((UnionAllOperator) opRef
+ .getValue()).getVariableMappings().iterator();
+ while (iter.hasNext()) {
+ Triple<LogicalVariable, LogicalVariable, LogicalVariable> varMapping = iter.next();
+ survivedUnionSourceVarSet.add(varMapping.first);
+ survivedUnionSourceVarSet.add(varMapping.second);
+ }
+ }
+
+ return assignVarsSetForThisOp;
+ }
+
+ private void removeUnusedAssigns(Mutable<ILogicalOperator> opRef, IOptimizationContext context)
+ throws AlgebricksException {
+
AbstractLogicalOperator op = (AbstractLogicalOperator) opRef.getValue();
- while (removeFromAssigns(op, toRemove, context) == 0) {
+
+ Set<LogicalVariable> assignVarsSetForThisOp = removeAssignVarFromConsideration(opRef);
+
+ while (removeFromAssigns(op, assignVarsSetForThisOp, context) == 0) {
if (op.getOperatorTag() == LogicalOperatorTag.AGGREGATE) {
break;
}
op = (AbstractLogicalOperator) op.getInputs().get(0).getValue();
opRef.setValue(op);
+ assignVarsSetForThisOp = removeAssignVarFromConsideration(opRef);
}
+
Iterator<Mutable<ILogicalOperator>> childIter = op.getInputs().iterator();
while (childIter.hasNext()) {
Mutable<ILogicalOperator> cRef = childIter.next();
- removeUnusedAssigns(cRef, toRemove, context);
+ removeUnusedAssigns(cRef, context);
}
+
if (op.hasNestedPlans()) {
AbstractOperatorWithNestedPlans opWithNest = (AbstractOperatorWithNestedPlans) op;
Iterator<ILogicalPlan> planIter = opWithNest.getNestedPlans().iterator();
while (planIter.hasNext()) {
ILogicalPlan p = planIter.next();
for (Mutable<ILogicalOperator> r : p.getRoots()) {
- removeUnusedAssigns(r, toRemove, context);
+ removeUnusedAssigns(r, context);
}
}
@@ -125,31 +199,37 @@
AssignOperator assign = (AssignOperator) op;
if (removeUnusedVarsAndExprs(toRemove, assign.getVariables(), assign.getExpressions())) {
context.computeAndSetTypeEnvironmentForOperator(assign);
+ isTransformed = true;
}
return assign.getVariables().size();
case AGGREGATE:
AggregateOperator agg = (AggregateOperator) op;
if (removeUnusedVarsAndExprs(toRemove, agg.getVariables(), agg.getExpressions())) {
context.computeAndSetTypeEnvironmentForOperator(agg);
+ isTransformed = true;
}
return agg.getVariables().size();
case UNNEST:
UnnestOperator uOp = (UnnestOperator) op;
LogicalVariable pVar = uOp.getPositionalVariable();
- if (pVar != null && toRemove.contains(pVar)) {
+ if (pVar != null && toRemove != null && toRemove.contains(pVar)) {
uOp.setPositionalVariable(null);
+ assignedVarSet.remove(pVar);
+ isTransformed = true;
}
break;
case UNIONALL:
UnionAllOperator unionOp = (UnionAllOperator) op;
if (removeUnusedVarsFromUnionAll(unionOp, toRemove)) {
context.computeAndSetTypeEnvironmentForOperator(unionOp);
+ isTransformed = true;
}
return unionOp.getVariableMappings().size();
case GROUP:
GroupByOperator groupByOp = (GroupByOperator) op;
if (removeUnusedVarsFromGroupBy(groupByOp, toRemove)) {
context.computeAndSetTypeEnvironmentForOperator(groupByOp);
+ isTransformed = true;
}
return groupByOp.getGroupByList().size() + groupByOp.getNestedPlans().size()
+ groupByOp.getDecorList().size();
@@ -163,22 +243,28 @@
Iterator<Triple<LogicalVariable, LogicalVariable, LogicalVariable>> iter = unionOp.getVariableMappings()
.iterator();
boolean modified = false;
- Set<LogicalVariable> removeFromRemoveSet = new HashSet<LogicalVariable>();
- while (iter.hasNext()) {
- Triple<LogicalVariable, LogicalVariable, LogicalVariable> varMapping = iter.next();
- if (toRemove.contains(varMapping.third)) {
- iter.remove();
- modified = true;
+ if (toRemove != null && !toRemove.isEmpty()) {
+ while (iter.hasNext()) {
+ Triple<LogicalVariable, LogicalVariable, LogicalVariable> varMapping = iter.next();
+ if (toRemove.contains(varMapping.third)) {
+ iter.remove();
+ assignedVarSet.remove(varMapping.third);
+ modified = true;
+ } else {
+ // In case when the output variable of Union is survived,
+ // the source variables should not be removed.
+ survivedUnionSourceVarSet.add(varMapping.first);
+ survivedUnionSourceVarSet.add(varMapping.second);
+ }
}
- // In any case, make sure we do not removing these variables.
- removeFromRemoveSet.add(varMapping.first);
- removeFromRemoveSet.add(varMapping.second);
}
- toRemove.removeAll(removeFromRemoveSet);
return modified;
}
private boolean removeUnusedVarsFromGroupBy(GroupByOperator groupByOp, Set<LogicalVariable> toRemove) {
+ if (toRemove == null || toRemove.isEmpty()) {
+ return false;
+ }
Iterator<Pair<LogicalVariable, Mutable<ILogicalExpression>>> iter = groupByOp.getDecorList().iterator();
boolean modified = false;
while (iter.hasNext()) {
@@ -204,88 +290,127 @@
private boolean removeUnusedVarsAndExprs(Set<LogicalVariable> toRemove, List<LogicalVariable> varList,
List<Mutable<ILogicalExpression>> exprList) {
boolean changed = false;
- Iterator<LogicalVariable> varIter = varList.iterator();
- Iterator<Mutable<ILogicalExpression>> exprIter = exprList.iterator();
- while (varIter.hasNext()) {
- LogicalVariable v = varIter.next();
- exprIter.next();
- if (toRemove.contains(v)) {
- varIter.remove();
- exprIter.remove();
- changed = true;
+ if (toRemove != null && !toRemove.isEmpty()) {
+ Iterator<LogicalVariable> varIter = varList.iterator();
+ Iterator<Mutable<ILogicalExpression>> exprIter = exprList.iterator();
+ while (varIter.hasNext()) {
+ LogicalVariable v = varIter.next();
+ exprIter.next();
+ if (toRemove.contains(v)) {
+ varIter.remove();
+ exprIter.remove();
+ assignedVarSet.remove(v);
+ changed = true;
+ }
}
}
return changed;
}
- private void collectUnusedAssignedVars(AbstractLogicalOperator op, Set<LogicalVariable> toRemove, boolean first,
- IOptimizationContext context) throws AlgebricksException {
+ private void collectUnusedAssignedVars(Mutable<ILogicalOperator> opRef,
+ Set<LogicalVariable> accumulatedUsedVarFromRootSet, boolean first, IOptimizationContext context)
+ throws AlgebricksException {
+ AbstractLogicalOperator op = (AbstractLogicalOperator) opRef.getValue();
if (!first) {
context.addToDontApplySet(this, op);
}
- for (Mutable<ILogicalOperator> c : op.getInputs()) {
- collectUnusedAssignedVars((AbstractLogicalOperator) c.getValue(), toRemove, false, context);
- }
- if (op.hasNestedPlans()) {
- AbstractOperatorWithNestedPlans opWithNested = (AbstractOperatorWithNestedPlans) op;
- for (ILogicalPlan plan : opWithNested.getNestedPlans()) {
- for (Mutable<ILogicalOperator> r : plan.getRoots()) {
- collectUnusedAssignedVars((AbstractLogicalOperator) r.getValue(), toRemove, false, context);
- }
- }
- }
- boolean removeUsedVars = true;
- Set<LogicalVariable> reBoundDecorVars = new HashSet<>();
+ Set<LogicalVariable> assignVarsSetInThisOp = new HashSet<>();
+ Set<LogicalVariable> usedVarsSetInThisOp = new HashSet<>();
+
+ // Add used variables in this operator to the accumulated used variables set?
+ boolean addUsedVarsInThisOp = true;
+ // ASSIGN, AGGREGATE, UNNEST, UNIONALL, or GROUP operator found?
+ boolean targetOpFound = false;
+
switch (op.getOperatorTag()) {
case ASSIGN:
AssignOperator assign = (AssignOperator) op;
- toRemove.addAll(assign.getVariables());
+ assignVarsSetInThisOp.addAll(assign.getVariables());
+ targetOpFound = true;
break;
case AGGREGATE:
AggregateOperator agg = (AggregateOperator) op;
- toRemove.addAll(agg.getVariables());
+ assignVarsSetInThisOp.addAll(agg.getVariables());
+ targetOpFound = true;
break;
case UNNEST:
UnnestOperator uOp = (UnnestOperator) op;
LogicalVariable pVar = uOp.getPositionalVariable();
if (pVar != null) {
- toRemove.add(pVar);
+ assignVarsSetInThisOp.add(pVar);
+ targetOpFound = true;
}
break;
case UNIONALL:
UnionAllOperator unionOp = (UnionAllOperator) op;
for (Triple<LogicalVariable, LogicalVariable, LogicalVariable> varMapping : unionOp
.getVariableMappings()) {
- toRemove.add(varMapping.third);
+ assignVarsSetInThisOp.add(varMapping.third);
}
- removeUsedVars = false;
+ targetOpFound = true;
+ // Don't add used variables in UNIONALL.
+ addUsedVarsInThisOp = false;
break;
case GROUP:
GroupByOperator groupByOp = (GroupByOperator) op;
for (Pair<LogicalVariable, Mutable<ILogicalExpression>> decorMapping : groupByOp.getDecorList()) {
LogicalVariable decorVar = decorMapping.first;
if (decorVar != null) {
- toRemove.add(decorVar);
+ assignVarsSetInThisOp.add(decorVar);
+ targetOpFound = true;
} else {
// A decor var mapping can have a variable reference expression without a new variable
// definition, which is for rebinding the referred variable.
VariableReferenceExpression varExpr = (VariableReferenceExpression) decorMapping.second
.getValue();
LogicalVariable reboundDecorVar = varExpr.getVariableReference();
- toRemove.add(reboundDecorVar);
- reBoundDecorVars.add(reboundDecorVar);
+ assignVarsSetInThisOp.add(reboundDecorVar);
}
}
break;
default:
break;
}
- if (removeUsedVars) {
- List<LogicalVariable> used = new LinkedList<LogicalVariable>();
- VariableUtilities.getUsedVariables(op, used);
- toRemove.removeAll(used);
- toRemove.addAll(reBoundDecorVars);
+
+ if (targetOpFound) {
+ assignedVarMap.put(opRef, assignVarsSetInThisOp);
+ assignedVarSet.addAll(assignVarsSetInThisOp);
+ }
+
+ if (addUsedVarsInThisOp) {
+ VariableUtilities.getUsedVariables(op, usedVarsSetInThisOp);
+ accumulatedUsedVarFromRootSet.addAll(usedVarsSetInThisOp);
+ // We may have visited this operator before if there are multiple
+ // paths in the plan.
+ if (accumulatedUsedVarFromRootMap.containsKey(opRef)) {
+ accumulatedUsedVarFromRootMap.get(opRef).addAll(usedVarsSetInThisOp);
+ } else {
+ accumulatedUsedVarFromRootMap.put(opRef, new HashSet<LogicalVariable>(accumulatedUsedVarFromRootSet));
+ }
+ } else {
+ accumulatedUsedVarFromRootMap.put(opRef, new HashSet<LogicalVariable>(accumulatedUsedVarFromRootSet));
+ }
+
+ for (Mutable<ILogicalOperator> c : op.getInputs()) {
+ collectUnusedAssignedVars(c, new HashSet<LogicalVariable>(accumulatedUsedVarFromRootSet), false, context);
+ }
+
+ if (op.hasNestedPlans()) {
+ AbstractOperatorWithNestedPlans opWithNested = (AbstractOperatorWithNestedPlans) op;
+ for (ILogicalPlan plan : opWithNested.getNestedPlans()) {
+ for (Mutable<ILogicalOperator> r : plan.getRoots()) {
+ collectUnusedAssignedVars(r, new HashSet<LogicalVariable>(accumulatedUsedVarFromRootSet), false,
+ context);
+ }
+ }
}
}
+ private void clear() {
+ assignedVarMap.clear();
+ assignedVarSet.clear();
+ accumulatedUsedVarFromRootMap.clear();
+ survivedUnionSourceVarSet.clear();
+ isTransformed = false;
+ }
}