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Consider number of predicates at each level in rewriting cost model
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6 files changed

+380
-117
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6 files changed

+380
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‎fdb-record-layer-core/src/main/java/com/apple/foundationdb/record/query/plan/cascades/RewritingCostModel.java‎

Lines changed: 20 additions & 6 deletions
Original file line numberDiff line numberDiff line change
@@ -24,19 +24,22 @@
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import com.apple.foundationdb.annotation.SpotBugsSuppressWarnings;
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import com.apple.foundationdb.record.query.plan.RecordQueryPlannerConfiguration;
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import com.apple.foundationdb.record.query.plan.cascades.expressions.RelationalExpression;
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import com.apple.foundationdb.record.query.plan.cascades.properties.PredicateCountByLevelProperty;
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import javax.annotation.Nonnull;
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import static com.apple.foundationdb.record.query.plan.cascades.properties.ExpressionCountProperty.selectCount;
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import static com.apple.foundationdb.record.query.plan.cascades.properties.ExpressionCountProperty.tableFunctionCount;
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import static com.apple.foundationdb.record.query.plan.cascades.properties.PredicateComplexityProperty.predicateComplexity;
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import static com.apple.foundationdb.record.query.plan.cascades.properties.PredicateHeightProperty.predicateHeight;
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import static com.apple.foundationdb.record.query.plan.cascades.properties.PredicateCountByLevelProperty.predicateCountByLevel;
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import static com.apple.foundationdb.record.query.plan.cascades.properties.PredicateCountProperty.predicateCount;
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/**
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* Cost model for {@link PlannerPhase#REWRITING}. TODO To be fleshed out whe we have actual rules.
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*/
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@API(API.Status.EXPERIMENTAL)
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@SpotBugsSuppressWarnings("SE_COMPARATOR_SHOULD_BE_SERIALIZABLE")
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@SuppressWarnings("PMD.TooManyStaticImports")
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public class RewritingCostModel implements CascadesCostModel {
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@Nonnull
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private final RecordQueryPlannerConfiguration configuration;
@@ -72,12 +75,23 @@ public int compare(final RelationalExpression a, final RelationalExpression b) {
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}
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//
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// Pick the expression where predicates have been pushed down as far as they can go
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// Pick the expression where that has the least number of predicates overall
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//
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int aPredicateHeight = predicateHeight().evaluate(a);
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int bPredicateHeight = predicateHeight().evaluate(b);
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if (aPredicateHeight != bPredicateHeight) {
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return Integer.compare(aPredicateHeight, bPredicateHeight);
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int aPredicateCount = predicateCount().evaluate(a);
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int bPredicateCount = predicateCount().evaluate(b);
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if (aPredicateCount != bPredicateCount) {
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return Integer.compare(aPredicateCount, bPredicateCount);
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}
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//
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// Pick the expression where it has the higher number of predicates at a lower level
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//
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PredicateCountByLevelProperty.PredicateCountByLevelInfo aPredicateCountByLevel = predicateCountByLevel().evaluate(a);
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PredicateCountByLevelProperty.PredicateCountByLevelInfo bPredicateCountByLevel = predicateCountByLevel().evaluate(b);
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int levelByLevelComparison = PredicateCountByLevelProperty.PredicateCountByLevelInfo.compare(aPredicateCountByLevel, bPredicateCountByLevel);
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if (levelByLevelComparison != 0) {
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// Choose the expression that has more predicates at a lower level
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return -levelByLevelComparison;
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}
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//

‎fdb-record-layer-core/src/main/java/com/apple/foundationdb/record/query/plan/cascades/properties/PredicateCountByLevelProperty.java‎

Lines changed: 146 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,146 @@
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/*
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* PredicateCountByLevelProperty.java
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*
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* This source file is part of the FoundationDB open source project
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*
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* Copyright 2015-2025 Apple Inc. and the FoundationDB project authors
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
15+
* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package com.apple.foundationdb.record.query.plan.cascades.properties;
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import com.apple.foundationdb.record.query.plan.cascades.ExpressionProperty;
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import com.apple.foundationdb.record.query.plan.cascades.Reference;
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import com.apple.foundationdb.record.query.plan.cascades.SimpleExpressionVisitor;
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import com.apple.foundationdb.record.query.plan.cascades.expressions.RelationalExpression;
27+
import com.apple.foundationdb.record.query.plan.cascades.expressions.RelationalExpressionVisitor;
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import com.apple.foundationdb.record.query.plan.cascades.expressions.RelationalExpressionWithPredicates;
29+
import com.google.common.collect.ImmutableMap;
30+
import com.google.common.collect.Iterables;
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import javax.annotation.Nonnull;
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import java.util.Collection;
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import java.util.Collections;
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import java.util.HashMap;
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import java.util.List;
37+
import java.util.Map;
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import java.util.function.BiFunction;
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public class PredicateCountByLevelProperty implements ExpressionProperty<PredicateCountByLevelProperty.PredicateCountByLevelInfo> {
41+
private static final PredicateCountByLevelProperty PREDICATE_COUNT_BY_LEVEL = new PredicateCountByLevelProperty();
42+
43+
private PredicateCountByLevelProperty() {
44+
// prevent outside instantiation
45+
}
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47+
@Nonnull
48+
@Override
49+
public RelationalExpressionVisitor<PredicateCountByLevelInfo> createVisitor() {
50+
return PredicateCountByLevelVisitor.VISITOR;
51+
}
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53+
public PredicateCountByLevelInfo evaluate(RelationalExpression expression) {
54+
return createVisitor().visit(expression);
55+
}
56+
57+
@Nonnull
58+
public static PredicateCountByLevelProperty predicateCountByLevel() {
59+
return PREDICATE_COUNT_BY_LEVEL;
60+
}
61+
62+
public static final class PredicateCountByLevelInfo {
63+
private final Map<Integer, Integer> levelToPredicateCount;
64+
private final int highestLevel;
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66+
private PredicateCountByLevelInfo(Map<Integer, Integer> levelToPredicateCount, int highestLevel) {
67+
this.levelToPredicateCount = levelToPredicateCount;
68+
this.highestLevel = highestLevel;
69+
}
70+
71+
public static PredicateCountByLevelInfo combine(Collection<? extends PredicateCountByLevelInfo> heightInfos, BiFunction<Integer, Integer, Integer> combineFunc) {
72+
final Map<Integer, Integer> newLevelToComplexityMap = new HashMap<>();
73+
int heightLevel = 0;
74+
for (PredicateCountByLevelInfo heightInfo : heightInfos) {
75+
for (var entry : heightInfo.getLevelToPredicateCount().entrySet()) {
76+
newLevelToComplexityMap.put(entry.getKey(), combineFunc.apply(newLevelToComplexityMap.getOrDefault(entry.getKey(), 0), entry.getValue()));
77+
}
78+
heightLevel = Integer.max(heightLevel, heightInfo.getHighestLevel());
79+
}
80+
return new PredicateCountByLevelInfo(newLevelToComplexityMap, heightLevel);
81+
}
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83+
public Map<Integer, Integer> getLevelToPredicateCount() {
84+
return Collections.unmodifiableMap(levelToPredicateCount);
85+
}
86+
87+
public int getHighestLevel() {
88+
return highestLevel;
89+
}
90+
91+
/**
92+
* Compares two {@code PredicateHeightInfo} instances level by level.
93+
*
94+
* @param a the first {@code PredicateHeightInfo} to compare
95+
* @param b the second {@code PredicateHeightInfo} to compare
96+
* @return the value {@code 0} if {@code a} have the same number of predicates at each level as {@code b};
97+
* a value less than {@code 0} if a {@code a} has fewer predicates than {@code b} at a
98+
* lower level or if {@code a} has a lower number of levels with predicates; and
99+
* a value greater than {@code 0} if {@code b} has fewer predicates than {@code a} at a
100+
* lower level or if {@code b} has a lower number of levels with predicates.
101+
* @since 1.7
102+
*/
103+
public static int compare(PredicateCountByLevelInfo a, PredicateCountByLevelInfo b) {
104+
for (int currentLevel = 0; currentLevel < Integer.max(a.getHighestLevel(), b.getHighestLevel()); currentLevel++) {
105+
var aLevelComplexity = a.getLevelToPredicateCount().getOrDefault(currentLevel, 0);
106+
var bLevelComplexity = b.getLevelToPredicateCount().getOrDefault(currentLevel, 0);
107+
var levelComparison = Integer.compare(aLevelComplexity, bLevelComplexity);
108+
if (levelComparison != 0) {
109+
return levelComparison;
110+
}
111+
}
112+
return 0;
113+
}
114+
}
115+
116+
private static final class PredicateCountByLevelVisitor implements SimpleExpressionVisitor<PredicateCountByLevelInfo> {
117+
private static final PredicateCountByLevelVisitor VISITOR = new PredicateCountByLevelVisitor();
118+
119+
@Nonnull
120+
@Override
121+
public PredicateCountByLevelInfo evaluateAtExpression(@Nonnull final RelationalExpression expression, @Nonnull final List<PredicateCountByLevelInfo> childResults) {
122+
var lowerLevels = PredicateCountByLevelInfo.combine(childResults, Integer::sum);
123+
var currentLevel = childResults.stream().mapToInt(PredicateCountByLevelInfo::getHighestLevel).max().orElse(0) + 1;
124+
var currentLevelPredicates = 0;
125+
if (expression instanceof RelationalExpressionWithPredicates) {
126+
currentLevelPredicates = ((RelationalExpressionWithPredicates)expression).getPredicates().size();
127+
}
128+
return new PredicateCountByLevelInfo(
129+
ImmutableMap.<Integer, Integer>builder()
130+
.putAll(lowerLevels.getLevelToPredicateCount())
131+
.put(currentLevel, currentLevelPredicates)
132+
.build(),
133+
currentLevel
134+
);
135+
}
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137+
@Nonnull
138+
@Override
139+
public PredicateCountByLevelInfo evaluateAtRef(@Nonnull final Reference ref, @Nonnull final List<PredicateCountByLevelInfo> memberResults) {
140+
if (memberResults.size() == 1) {
141+
return Iterables.getOnlyElement(memberResults);
142+
}
143+
return PredicateCountByLevelInfo.combine(memberResults, Integer::max);
144+
}
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}
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}

‎fdb-record-layer-core/src/main/java/com/apple/foundationdb/record/query/plan/cascades/properties/PredicateCountProperty.java‎

Lines changed: 78 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,78 @@
1+
/*
2+
* PredicateCountProperty.java
3+
*
4+
* This source file is part of the FoundationDB open source project
5+
*
6+
* Copyright 2015-2025 Apple Inc. and the FoundationDB project authors
7+
*
8+
* Licensed under the Apache License, Version 2.0 (the "License");
9+
* you may not use this file except in compliance with the License.
10+
* You may obtain a copy of the License at
11+
*
12+
* http://www.apache.org/licenses/LICENSE-2.0
13+
*
14+
* Unless required by applicable law or agreed to in writing, software
15+
* distributed under the License is distributed on an "AS IS" BASIS,
16+
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
17+
* See the License for the specific language governing permissions and
18+
* limitations under the License.
19+
*/
20+
21+
package com.apple.foundationdb.record.query.plan.cascades.properties;
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23+
import com.apple.foundationdb.record.query.plan.cascades.ExpressionProperty;
24+
import com.apple.foundationdb.record.query.plan.cascades.Reference;
25+
import com.apple.foundationdb.record.query.plan.cascades.SimpleExpressionVisitor;
26+
import com.apple.foundationdb.record.query.plan.cascades.expressions.RelationalExpression;
27+
import com.apple.foundationdb.record.query.plan.cascades.expressions.RelationalExpressionVisitor;
28+
import com.apple.foundationdb.record.query.plan.cascades.expressions.RelationalExpressionWithPredicates;
29+
import com.google.common.collect.Iterables;
30+
31+
import javax.annotation.Nonnull;
32+
import java.util.List;
33+
34+
public class PredicateCountProperty implements ExpressionProperty<Integer> {
35+
private static final PredicateCountProperty PREDICATE_COUNT = new PredicateCountProperty();
36+
37+
private PredicateCountProperty() {
38+
// prevent outside instantiation
39+
}
40+
41+
@Nonnull
42+
@Override
43+
public RelationalExpressionVisitor<Integer> createVisitor() {
44+
return PredicateCountVisitor.VISITOR;
45+
}
46+
47+
public int evaluate(RelationalExpression expression) {
48+
return createVisitor().visit(expression);
49+
}
50+
51+
@Nonnull
52+
public static PredicateCountProperty predicateCount() {
53+
return PREDICATE_COUNT;
54+
}
55+
56+
private static final class PredicateCountVisitor implements SimpleExpressionVisitor<Integer> {
57+
private static final PredicateCountVisitor VISITOR = new PredicateCountVisitor();
58+
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@Nonnull
60+
@Override
61+
public Integer evaluateAtExpression(@Nonnull final RelationalExpression expression, @Nonnull final List<Integer> childResults) {
62+
final var childPredicates = childResults.stream().mapToInt(Integer::intValue).sum();
63+
if (!(expression instanceof RelationalExpressionWithPredicates)) {
64+
return childPredicates;
65+
}
66+
return childPredicates + ((RelationalExpressionWithPredicates)expression).getPredicates().size();
67+
}
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@Nonnull
70+
@Override
71+
public Integer evaluateAtRef(@Nonnull final Reference ref, @Nonnull final List<Integer> memberResults) {
72+
if (memberResults.size() == 1) {
73+
return Iterables.getOnlyElement(memberResults);
74+
}
75+
return memberResults.stream().mapToInt(Integer::intValue).max().orElse(0);
76+
}
77+
}
78+
}

‎fdb-record-layer-core/src/main/java/com/apple/foundationdb/record/query/plan/cascades/properties/PredicateHeightProperty.java‎

Lines changed: 0 additions & 111 deletions
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