[fix](nerieds) avoid redundant enumeration same LogicalProject in memo (

apache#38317) 1. use set to compare project 2. use map to store enforcer 3. avoid genarate useless project under bottom join when do join reorder
eldenmoon · Aug 4, 2024 · cdaabef · cdaabef
1 parent 9a216fe
commit cdaabef
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Showing 23 changed files with 230 additions and 119 deletions.
diff --git a/fe/fe-core/src/main/java/org/apache/doris/nereids/NereidsPlanner.java b/fe/fe-core/src/main/java/org/apache/doris/nereids/NereidsPlanner.java
@@ -428,7 +428,7 @@ private PhysicalPlan chooseBestPlan(Group rootGroup, PhysicalProperties physical
             GroupExpression groupExpression = rootGroup.getLowestCostPlan(physicalProperties).orElseThrow(
                     () -> new AnalysisException("lowestCostPlans with physicalProperties("
                             + physicalProperties + ") doesn't exist in root group")).second;
-            if (rootGroup.getEnforcers().contains(groupExpression)) {
+            if (rootGroup.getEnforcers().containsKey(groupExpression)) {
                 rootGroup.addChosenEnforcerId(groupExpression.getId().asInt());
                 rootGroup.addChosenEnforcerProperties(physicalProperties);
             } else {

diff --git a/fe/fe-core/src/main/java/org/apache/doris/nereids/jobs/cascades/ApplyRuleJob.java b/fe/fe-core/src/main/java/org/apache/doris/nereids/jobs/cascades/ApplyRuleJob.java
@@ -74,6 +74,11 @@ public final void execute() throws AnalysisException {
         GroupExpressionMatching groupExpressionMatching
                 = new GroupExpressionMatching(rule.getPattern(), groupExpression);
         for (Plan plan : groupExpressionMatching) {
+            if (rule.isExploration()
+                    && context.getCascadesContext().getMemo().getGroupExpressionsSize() > context.getCascadesContext()
+                    .getConnectContext().getSessionVariable().memoMaxGroupExpressionSize) {
+                break;
+            }
             List<Plan> newPlans = rule.transform(plan, context.getCascadesContext());
             for (Plan newPlan : newPlans) {
                 if (newPlan == plan) {

diff --git a/fe/fe-core/src/main/java/org/apache/doris/nereids/memo/Group.java b/fe/fe-core/src/main/java/org/apache/doris/nereids/memo/Group.java
@@ -59,7 +59,7 @@ public class Group {
 
     private final List<GroupExpression> logicalExpressions = Lists.newArrayList();
     private final List<GroupExpression> physicalExpressions = Lists.newArrayList();
-    private final List<GroupExpression> enforcers = Lists.newArrayList();
+    private final Map<GroupExpression, GroupExpression> enforcers = Maps.newHashMap();
     private boolean isStatsReliable = true;
     private LogicalProperties logicalProperties;
 
@@ -239,10 +239,10 @@ public GroupExpression getBestPlan(PhysicalProperties properties) {
 
     public void addEnforcer(GroupExpression enforcer) {
         enforcer.setOwnerGroup(this);
-        enforcers.add(enforcer);
+        enforcers.put(enforcer, enforcer);
     }
 
-    public List<GroupExpression> getEnforcers() {
+    public Map<GroupExpression, GroupExpression> getEnforcers() {
         return enforcers;
     }
 
@@ -346,9 +346,9 @@ public void mergeTo(Group target) {
         parentExpressions.keySet().forEach(parent -> target.addParentExpression(parent));
 
         // move enforcers Ownership
-        enforcers.forEach(ge -> ge.children().set(0, target));
+        enforcers.forEach((k, v) -> k.children().set(0, target));
         // TODO: dedup?
-        enforcers.forEach(enforcer -> target.addEnforcer(enforcer));
+        enforcers.forEach((k, v) -> target.addEnforcer(k));
         enforcers.clear();
 
         // move LogicalExpression PhysicalExpression Ownership
@@ -458,7 +458,7 @@ public String toString() {
             str.append("    ").append(physicalExpression).append("\n");
         }
         str.append("  enforcers:\n");
-        for (GroupExpression enforcer : enforcers) {
+        for (GroupExpression enforcer : enforcers.keySet()) {
             str.append("    ").append(enforcer).append("\n");
         }
         if (!chosenEnforcerIdList.isEmpty()) {

diff --git a/fe/fe-core/src/main/java/org/apache/doris/nereids/memo/Memo.java b/fe/fe-core/src/main/java/org/apache/doris/nereids/memo/Memo.java
@@ -552,8 +552,7 @@ public void mergeGroup(Group source, Group destination, HashMap<Long, Group> pla
                 return;
             }
             Group parentOwnerGroup = srcParent.getOwnerGroup();
-            HashSet<GroupExpression> enforcers = new HashSet<>(parentOwnerGroup.getEnforcers());
-            if (enforcers.contains(srcParent)) {
+            if (parentOwnerGroup.getEnforcers().containsKey(srcParent)) {
                 continue;
             }
             needReplaceChild.add(srcParent);
@@ -946,7 +945,7 @@ private List<GroupExpression> extractGroupExpressionSatisfyProp(Group group, Phy
         List<GroupExpression> exprs = Lists.newArrayList(bestExpr);
         Set<GroupExpression> hasVisited = new HashSet<>();
         hasVisited.add(bestExpr);
-        Stream.concat(group.getPhysicalExpressions().stream(), group.getEnforcers().stream())
+        Stream.concat(group.getPhysicalExpressions().stream(), group.getEnforcers().keySet().stream())
                 .forEach(groupExpression -> {
                     if (!groupExpression.getInputPropertiesListOrEmpty(prop).isEmpty()
                             && !groupExpression.equals(bestExpr) && !hasVisited.contains(groupExpression)) {
@@ -969,7 +968,7 @@ private List<List<PhysicalProperties>> extractInputProperties(GroupExpression gr
         res.add(groupExpression.getInputPropertiesList(prop));
 
         // return optimized input for enforcer
-        if (groupExpression.getOwnerGroup().getEnforcers().contains(groupExpression)) {
+        if (groupExpression.getOwnerGroup().getEnforcers().containsKey(groupExpression)) {
             return res;
         }
 

diff --git a/fe/fe-core/src/main/java/org/apache/doris/nereids/rules/Rule.java b/fe/fe-core/src/main/java/org/apache/doris/nereids/rules/Rule.java
@@ -64,6 +64,10 @@ public boolean isRewrite() {
         return ruleType.getRuleTypeClass() == RuleTypeClass.REWRITE;
     }
 
+    public boolean isExploration() {
+        return ruleType.getRuleTypeClass() == RuleTypeClass.EXPLORATION;
+    }
+
     @Override
     public String toString() {
         return getRuleType().toString();

diff --git a/fe/fe-core/src/main/java/org/apache/doris/nereids/rules/RuleType.java b/fe/fe-core/src/main/java/org/apache/doris/nereids/rules/RuleType.java
@@ -381,29 +381,29 @@ public enum RuleType {
     EAGER_SPLIT(RuleTypeClass.EXPLORATION),
 
     EXPLORATION_SENTINEL(RuleTypeClass.EXPLORATION),
-    MATERIALIZED_VIEW_PROJECT_JOIN(RuleTypeClass.EXPLORATION),
-    MATERIALIZED_VIEW_FILTER_JOIN(RuleTypeClass.EXPLORATION),
-    MATERIALIZED_VIEW_PROJECT_FILTER_JOIN(RuleTypeClass.EXPLORATION),
-    MATERIALIZED_VIEW_FILTER_PROJECT_JOIN(RuleTypeClass.EXPLORATION),
-    MATERIALIZED_VIEW_ONLY_JOIN(RuleTypeClass.EXPLORATION),
-
-    MATERIALIZED_VIEW_PROJECT_AGGREGATE(RuleTypeClass.EXPLORATION),
-    MATERIALIZED_VIEW_FILTER_AGGREGATE(RuleTypeClass.EXPLORATION),
-    MATERIALIZED_VIEW_PROJECT_FILTER_AGGREGATE(RuleTypeClass.EXPLORATION),
-    MATERIALIZED_VIEW_FILTER_PROJECT_AGGREGATE(RuleTypeClass.EXPLORATION),
-    MATERIALIZED_VIEW_ONLY_AGGREGATE(RuleTypeClass.EXPLORATION),
-
-    MATERIALIZED_VIEW_PROJECT_AGGREGATE_ON_NONE_AGGREGATE(RuleTypeClass.EXPLORATION),
-    MATERIALIZED_VIEW_FILTER_AGGREGATE_ON_NONE_AGGREGATE(RuleTypeClass.EXPLORATION),
-    MATERIALIZED_VIEW_PROJECT_FILTER_AGGREGATE_ON_NONE_AGGREGATE(RuleTypeClass.EXPLORATION),
-    MATERIALIZED_VIEW_FILTER_PROJECT_AGGREGATE_ON_NONE_AGGREGATE(RuleTypeClass.EXPLORATION),
-    MATERIALIZED_VIEW_ONLY_AGGREGATE_ON_NONE_AGGREGATE(RuleTypeClass.EXPLORATION),
-
-    MATERIALIZED_VIEW_FILTER_SCAN(RuleTypeClass.EXPLORATION),
-    MATERIALIZED_VIEW_PROJECT_SCAN(RuleTypeClass.EXPLORATION),
-    MATERIALIZED_VIEW_FILTER_PROJECT_SCAN(RuleTypeClass.EXPLORATION),
-    MATERIALIZED_VIEW_PROJECT_FILTER_SCAN(RuleTypeClass.EXPLORATION),
-    MATERIALIZED_VIEW_ONLY_SCAN(RuleTypeClass.EXPLORATION),
+    MATERIALIZED_VIEW_PROJECT_JOIN(RuleTypeClass.MATERIALIZE_VIEW),
+    MATERIALIZED_VIEW_FILTER_JOIN(RuleTypeClass.MATERIALIZE_VIEW),
+    MATERIALIZED_VIEW_PROJECT_FILTER_JOIN(RuleTypeClass.MATERIALIZE_VIEW),
+    MATERIALIZED_VIEW_FILTER_PROJECT_JOIN(RuleTypeClass.MATERIALIZE_VIEW),
+    MATERIALIZED_VIEW_ONLY_JOIN(RuleTypeClass.MATERIALIZE_VIEW),
+
+    MATERIALIZED_VIEW_PROJECT_AGGREGATE(RuleTypeClass.MATERIALIZE_VIEW),
+    MATERIALIZED_VIEW_FILTER_AGGREGATE(RuleTypeClass.MATERIALIZE_VIEW),
+    MATERIALIZED_VIEW_PROJECT_FILTER_AGGREGATE(RuleTypeClass.MATERIALIZE_VIEW),
+    MATERIALIZED_VIEW_FILTER_PROJECT_AGGREGATE(RuleTypeClass.MATERIALIZE_VIEW),
+    MATERIALIZED_VIEW_ONLY_AGGREGATE(RuleTypeClass.MATERIALIZE_VIEW),
+
+    MATERIALIZED_VIEW_PROJECT_AGGREGATE_ON_NONE_AGGREGATE(RuleTypeClass.MATERIALIZE_VIEW),
+    MATERIALIZED_VIEW_FILTER_AGGREGATE_ON_NONE_AGGREGATE(RuleTypeClass.MATERIALIZE_VIEW),
+    MATERIALIZED_VIEW_PROJECT_FILTER_AGGREGATE_ON_NONE_AGGREGATE(RuleTypeClass.MATERIALIZE_VIEW),
+    MATERIALIZED_VIEW_FILTER_PROJECT_AGGREGATE_ON_NONE_AGGREGATE(RuleTypeClass.MATERIALIZE_VIEW),
+    MATERIALIZED_VIEW_ONLY_AGGREGATE_ON_NONE_AGGREGATE(RuleTypeClass.MATERIALIZE_VIEW),
+
+    MATERIALIZED_VIEW_FILTER_SCAN(RuleTypeClass.MATERIALIZE_VIEW),
+    MATERIALIZED_VIEW_PROJECT_SCAN(RuleTypeClass.MATERIALIZE_VIEW),
+    MATERIALIZED_VIEW_FILTER_PROJECT_SCAN(RuleTypeClass.MATERIALIZE_VIEW),
+    MATERIALIZED_VIEW_PROJECT_FILTER_SCAN(RuleTypeClass.MATERIALIZE_VIEW),
+    MATERIALIZED_VIEW_ONLY_SCAN(RuleTypeClass.MATERIALIZE_VIEW),
 
     // implementation rules
     LOGICAL_ONE_ROW_RELATION_TO_PHYSICAL_ONE_ROW_RELATION(RuleTypeClass.IMPLEMENTATION),
@@ -491,6 +491,7 @@ public <INPUT_TYPE extends Plan, OUTPUT_TYPE extends Plan> Rule build(
     enum RuleTypeClass {
         REWRITE,
         EXPLORATION,
+        MATERIALIZE_VIEW,
         // This type is used for unit test only.
         CHECK,
         IMPLEMENTATION,

diff --git a/fe/fe-core/src/main/java/org/apache/doris/nereids/rules/exploration/CBOUtils.java b/fe/fe-core/src/main/java/org/apache/doris/nereids/rules/exploration/CBOUtils.java
@@ -42,6 +42,13 @@ public static Set<Slot> joinChildConditionSlots(LogicalJoin<? extends Plan, ? ex
                 .collect(Collectors.toSet());
     }
 
+    public static Plan newProjectIfNeeded(Set<ExprId> requiredExprIds, Plan plan) {
+        if (requiredExprIds.equals(plan.getOutputExprIdSet())) {
+            return plan;
+        }
+        return newProject(requiredExprIds, plan);
+    }
+
     public static Plan newProject(Set<ExprId> requiredExprIds, Plan plan) {
         List<NamedExpression> projects = plan.getOutput().stream()
                 .filter(namedExpr -> requiredExprIds.contains(namedExpr.getExprId()))

diff --git a/...rc/main/java/org/apache/doris/nereids/rules/exploration/join/InnerJoinLAsscomProject.java b/...rc/main/java/org/apache/doris/nereids/rules/exploration/join/InnerJoinLAsscomProject.java
@@ -98,7 +98,7 @@ public Rule build() {
                     newTopHashConjuncts.forEach(expr -> topUsedExprIds.addAll(expr.getInputSlotExprIds()));
                     newTopOtherConjuncts.forEach(expr -> topUsedExprIds.addAll(expr.getInputSlotExprIds()));
                     Plan left = CBOUtils.newProject(topUsedExprIds, newBottomJoin);
-                    Plan right = CBOUtils.newProject(topUsedExprIds, b);
+                    Plan right = CBOUtils.newProjectIfNeeded(topUsedExprIds, b);
 
                     LogicalJoin<Plan, Plan> newTopJoin = bottomJoin.withConjunctsChildren(newTopHashConjuncts,
                             newTopOtherConjuncts, left, right, null);

diff --git a/...n/java/org/apache/doris/nereids/rules/exploration/join/InnerJoinLeftAssociateProject.java b/...n/java/org/apache/doris/nereids/rules/exploration/join/InnerJoinLeftAssociateProject.java
@@ -85,7 +85,7 @@ public Rule build() {
                     newTopHashConjuncts.forEach(expr -> topUsedExprIds.addAll(expr.getInputSlotExprIds()));
                     newTopOtherConjuncts.forEach(expr -> topUsedExprIds.addAll(expr.getInputSlotExprIds()));
                     Plan left = CBOUtils.newProject(topUsedExprIds, newBottomJoin);
-                    Plan right = CBOUtils.newProject(topUsedExprIds, c);
+                    Plan right = CBOUtils.newProjectIfNeeded(topUsedExprIds, c);
 
                     LogicalJoin<Plan, Plan> newTopJoin = bottomJoin.withConjunctsChildren(
                             newTopHashConjuncts, newTopOtherConjuncts, left, right, null);

diff --git a/.../java/org/apache/doris/nereids/rules/exploration/join/InnerJoinRightAssociateProject.java b/.../java/org/apache/doris/nereids/rules/exploration/join/InnerJoinRightAssociateProject.java
@@ -81,7 +81,7 @@ public Rule build() {
                     topProject.getProjects().forEach(expr -> topUsedExprIds.addAll(expr.getInputSlotExprIds()));
                     newTopHashConjuncts.forEach(expr -> topUsedExprIds.addAll(expr.getInputSlotExprIds()));
                     newTopOtherConjuncts.forEach(expr -> topUsedExprIds.addAll(expr.getInputSlotExprIds()));
-                    Plan left = CBOUtils.newProject(topUsedExprIds, a);
+                    Plan left = CBOUtils.newProjectIfNeeded(topUsedExprIds, a);
                     Plan right = CBOUtils.newProject(topUsedExprIds, newBottomJoin);
 
                     LogicalJoin<Plan, Plan> newTopJoin = bottomJoin.withConjunctsChildren(

diff --git a/.../org/apache/doris/nereids/rules/exploration/join/LogicalJoinSemiJoinTransposeProject.java b/.../org/apache/doris/nereids/rules/exploration/join/LogicalJoinSemiJoinTransposeProject.java
@@ -70,7 +70,7 @@ public List<Rule> buildRules() {
                                     .forEach(e -> topUsedExprIds.addAll(e.getInputSlotExprIds()));
                             Plan newBottomJoin = topJoin.withChildrenNoContext(a, c, null);
                             Plan left = CBOUtils.newProject(topUsedExprIds, newBottomJoin);
-                            Plan right = CBOUtils.newProject(topUsedExprIds, b);
+                            Plan right = CBOUtils.newProjectIfNeeded(topUsedExprIds, b);
 
                             Plan newTopJoin = bottomJoin.withChildrenNoContext(left, right, null);
                             return topProject.withChildren(newTopJoin);
@@ -102,7 +102,7 @@ public List<Rule> buildRules() {
                                     .forEach(e -> topUsedExprIds.addAll(e.getInputSlotExprIds()));
                             Plan newBottomJoin = topJoin.withChildrenNoContext(a, b, null);
                             Plan left = CBOUtils.newProject(topUsedExprIds, newBottomJoin);
-                            Plan right = CBOUtils.newProject(topUsedExprIds, c);
+                            Plan right = CBOUtils.newProjectIfNeeded(topUsedExprIds, c);
 
                             Plan newTopJoin = bottomJoin.withChildrenNoContext(left, right, null);
                             return topProject.withChildren(newTopJoin);

diff --git a/.../src/main/java/org/apache/doris/nereids/rules/exploration/join/OuterJoinAssocProject.java b/.../src/main/java/org/apache/doris/nereids/rules/exploration/join/OuterJoinAssocProject.java
@@ -104,7 +104,7 @@ public Rule build() {
                     topProject.getProjects().forEach(expr -> topUsedExprIds.addAll(expr.getInputSlotExprIds()));
                     bottomJoin.getHashJoinConjuncts().forEach(e -> topUsedExprIds.addAll(e.getInputSlotExprIds()));
                     bottomJoin.getOtherJoinConjuncts().forEach(e -> topUsedExprIds.addAll(e.getInputSlotExprIds()));
-                    Plan left = CBOUtils.newProject(topUsedExprIds, a);
+                    Plan left = CBOUtils.newProjectIfNeeded(topUsedExprIds, a);
                     Plan right = CBOUtils.newProject(topUsedExprIds, newBottomJoin);
 
                     LogicalJoin newTopJoin = bottomJoin.withChildrenNoContext(left, right, null);

diff --git a/...rc/main/java/org/apache/doris/nereids/rules/exploration/join/OuterJoinLAsscomProject.java b/...rc/main/java/org/apache/doris/nereids/rules/exploration/join/OuterJoinLAsscomProject.java
@@ -90,7 +90,7 @@ public Rule build() {
                     bottomJoin.getHashJoinConjuncts().forEach(e -> topUsedExprIds.addAll(e.getInputSlotExprIds()));
                     bottomJoin.getOtherJoinConjuncts().forEach(e -> topUsedExprIds.addAll(e.getInputSlotExprIds()));
                     Plan left = CBOUtils.newProject(topUsedExprIds, newBottomJoin);
-                    Plan right = CBOUtils.newProject(topUsedExprIds, b);
+                    Plan right = CBOUtils.newProjectIfNeeded(topUsedExprIds, b);
 
                     LogicalJoin newTopJoin = bottomJoin.withChildrenNoContext(left, right, null);
                     newTopJoin.getJoinReorderContext().copyFrom(topJoin.getJoinReorderContext());

diff --git a/...ava/org/apache/doris/nereids/rules/exploration/join/SemiJoinSemiJoinTransposeProject.java b/...ava/org/apache/doris/nereids/rules/exploration/join/SemiJoinSemiJoinTransposeProject.java
@@ -106,7 +106,7 @@ public Rule build() {
                     bottomSemi.getOtherJoinConjuncts().forEach(e -> topUsedExprIds.addAll(e.getInputSlotExprIds()));
 
                     Plan left = CBOUtils.newProject(topUsedExprIds, newBottomSemi);
-                    Plan right = CBOUtils.newProject(topUsedExprIds, b);
+                    Plan right = CBOUtils.newProjectIfNeeded(topUsedExprIds, b);
 
                     LogicalJoin newTopSemi = bottomSemi.withChildrenNoContext(left, right, null);
                     newTopSemi.getJoinReorderContext().copyFrom(topSemi.getJoinReorderContext());

diff --git a/fe/fe-core/src/main/java/org/apache/doris/nereids/trees/plans/logical/LogicalProject.java b/fe/fe-core/src/main/java/org/apache/doris/nereids/trees/plans/logical/LogicalProject.java
@@ -37,6 +37,8 @@
 import org.apache.doris.nereids.util.Utils;
 
 import com.google.common.base.Preconditions;
+import com.google.common.base.Supplier;
+import com.google.common.base.Suppliers;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableList.Builder;
 import com.google.common.collect.ImmutableSet;
@@ -47,6 +49,7 @@
 import java.util.Map;
 import java.util.Objects;
 import java.util.Optional;
+import java.util.Set;
 
 /**
  * Logical project plan.
@@ -55,6 +58,7 @@ public class LogicalProject<CHILD_TYPE extends Plan> extends LogicalUnary<CHILD_
         implements Project, OutputPrunable {
 
     private final List<NamedExpression> projects;
+    private final Supplier<Set<NamedExpression>> projectsSet;
     private final List<NamedExpression> excepts;
     private final boolean isDistinct;
 
@@ -84,6 +88,7 @@ private LogicalProject(List<NamedExpression> projects, List<NamedExpression> exc
         this.projects = projects.isEmpty()
                 ? ImmutableList.of(ExpressionUtils.selectMinimumColumn(child.get(0).getOutput()))
                 : projects;
+        this.projectsSet = Suppliers.memoize(() -> ImmutableSet.copyOf(this.projects));
         this.excepts = Utils.fastToImmutableList(excepts);
         this.isDistinct = isDistinct;
     }
@@ -139,7 +144,7 @@ public boolean equals(Object o) {
             return false;
         }
         LogicalProject<?> that = (LogicalProject<?>) o;
-        boolean equal = projects.equals(that.projects)
+        boolean equal = projectsSet.get().equals(that.projectsSet.get())
                 && excepts.equals(that.excepts)
                 && isDistinct == that.isDistinct;
         // TODO: should add exprId for UnBoundStar and BoundStar for equality comparison
@@ -151,7 +156,7 @@ public boolean equals(Object o) {
 
     @Override
     public int hashCode() {
-        return Objects.hash(projects);
+        return Objects.hash(projectsSet.get());
     }
 
     @Override

diff --git a/fe/fe-core/src/main/java/org/apache/doris/nereids/trees/plans/physical/PhysicalProject.java b/fe/fe-core/src/main/java/org/apache/doris/nereids/trees/plans/physical/PhysicalProject.java
@@ -34,19 +34,24 @@
 import org.apache.doris.statistics.Statistics;
 
 import com.google.common.base.Preconditions;
+import com.google.common.base.Supplier;
+import com.google.common.base.Suppliers;
 import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Lists;
 
 import java.util.List;
 import java.util.Objects;
 import java.util.Optional;
+import java.util.Set;
 
 /**
  * Physical project plan.
  */
 public class PhysicalProject<CHILD_TYPE extends Plan> extends PhysicalUnary<CHILD_TYPE> implements Project {
 
     private final List<NamedExpression> projects;
+    private final Supplier<Set<NamedExpression>> projectsSet;
     //multiLayerProjects is used to extract common expressions
     // projects: (A+B) * 2, (A+B) * 3
     // multiLayerProjects:
@@ -62,6 +67,7 @@ public PhysicalProject(List<NamedExpression> projects, Optional<GroupExpression>
             LogicalProperties logicalProperties, CHILD_TYPE child) {
         super(PlanType.PHYSICAL_PROJECT, groupExpression, logicalProperties, child);
         this.projects = ImmutableList.copyOf(Objects.requireNonNull(projects, "projects can not be null"));
+        this.projectsSet = Suppliers.memoize(() -> ImmutableSet.copyOf(this.projects));
     }
 
     public PhysicalProject(List<NamedExpression> projects, Optional<GroupExpression> groupExpression,
@@ -70,6 +76,7 @@ public PhysicalProject(List<NamedExpression> projects, Optional<GroupExpression>
         super(PlanType.PHYSICAL_PROJECT, groupExpression, logicalProperties, physicalProperties, statistics,
                 child);
         this.projects = ImmutableList.copyOf(Objects.requireNonNull(projects, "projects can not be null"));
+        this.projectsSet = Suppliers.memoize(() -> ImmutableSet.copyOf(this.projects));
     }
 
     public List<NamedExpression> getProjects() {
@@ -96,13 +103,13 @@ public boolean equals(Object o) {
         if (o == null || getClass() != o.getClass()) {
             return false;
         }
-        PhysicalProject that = (PhysicalProject) o;
-        return projects.equals(that.projects);
+        PhysicalProject<?> that = (PhysicalProject<?>) o;
+        return projectsSet.get().equals(that.projectsSet.get());
     }
 
     @Override
     public int hashCode() {
-        return Objects.hash(projects);
+        return Objects.hash(projectsSet.get());
     }
 
     @Override