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[Enhencement](Nereids) reduce child output rows if agg child is literal (#32188)

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with group by:
select max(1) from t1 group by c1; -> select 1 from (select c1 from t1 group by c1);
without group by:
select max(1) from t1; -> select max(1) from (select 1 from t1 limit 1) tmp;
This commit is contained in:
LiBinfeng
2024-04-03 12:23:41 +08:00
committed by yiguolei
parent 0ab8b57db7
commit 6798a24a27
5 changed files with 1370 additions and 0 deletions
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2
fe/fe-core/src/main/java/org/apache/doris/nereids/jobs/executor/Rewriter.java
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@ -117,6 +117,7 @@ import org.apache.doris.nereids.rules.rewrite.PushFilterInsideJoin;
import org.apache.doris.nereids.rules.rewrite.PushProjectIntoOneRowRelation;
import org.apache.doris.nereids.rules.rewrite.PushProjectIntoUnion;
import org.apache.doris.nereids.rules.rewrite.PushProjectThroughUnion;
import org.apache.doris.nereids.rules.rewrite.ReduceAggregateChildOutputRows;
import org.apache.doris.nereids.rules.rewrite.ReorderJoin;
import org.apache.doris.nereids.rules.rewrite.RewriteCteChildren;
import org.apache.doris.nereids.rules.rewrite.SplitLimit;
@ -203,6 +204,7 @@ public class Rewriter extends AbstractBatchJobExecutor {
new EliminateLimit(),
new EliminateFilter(),
new EliminateAggregate(),
new ReduceAggregateChildOutputRows(),
new EliminateJoinCondition(),
new EliminateAssertNumRows(),
new EliminateSemiJoin()

1
fe/fe-core/src/main/java/org/apache/doris/nereids/rules/RuleType.java
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@ -239,6 +239,7 @@ public enum RuleType {
MATERIALIZED_INDEX_PROJECT_SCAN(RuleTypeClass.REWRITE),
MATERIALIZED_INDEX_PROJECT_FILTER_SCAN(RuleTypeClass.REWRITE),
MATERIALIZED_INDEX_FILTER_PROJECT_SCAN(RuleTypeClass.REWRITE),
REDUCE_AGGREGATE_CHILD_OUTPUT_ROWS(RuleTypeClass.REWRITE),
OLAP_SCAN_PARTITION_PRUNE(RuleTypeClass.REWRITE),

89
fe/fe-core/src/main/java/org/apache/doris/nereids/rules/rewrite/ReduceAggregateChildOutputRows.java Normal file
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@ -0,0 +1,89 @@
// 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.doris.nereids.rules.rewrite;
import org.apache.doris.nereids.exceptions.AnalysisException;
import org.apache.doris.nereids.rules.Rule;
import org.apache.doris.nereids.rules.RuleType;
import org.apache.doris.nereids.trees.expressions.Alias;
import org.apache.doris.nereids.trees.expressions.Expression;
import org.apache.doris.nereids.trees.expressions.NamedExpression;
import org.apache.doris.nereids.trees.expressions.functions.agg.AggregateFunction;
import org.apache.doris.nereids.trees.expressions.functions.agg.Max;
import org.apache.doris.nereids.trees.expressions.functions.agg.Min;
import org.apache.doris.nereids.trees.plans.LimitPhase;
import org.apache.doris.nereids.trees.plans.logical.LogicalAggregate;
import org.apache.doris.nereids.trees.plans.logical.LogicalLimit;
import org.apache.doris.nereids.trees.plans.logical.LogicalProject;
import com.google.common.collect.ImmutableList;
import java.util.Set;
/** ReduceAggregateChildOutputRows
* with group by:
* select max(1) from t1 group by c1; -> select 1 from (select c1 from t1 group by c1);
* without group by:
* select max(1) from t1; -> select max(1) from (select 1 from t1 limit 1) tmp;
* */
public class ReduceAggregateChildOutputRows extends OneRewriteRuleFactory {
@Override
public Rule build() {
return logicalAggregate().then(agg -> {
Set<AggregateFunction> aggFunctions = agg.getAggregateFunctions();
// check whether we have aggregate(constant) in all aggregateFunctions
if (!(agg.child() instanceof LogicalLimit && ((LogicalLimit) agg.child()).getLimit() == 1)
|| aggFunctions.isEmpty() || !aggFunctions.stream().allMatch(
f -> (f instanceof Min || f instanceof Max)
&& (f.arity() == 1 && f.child(0).isConstant()))) {
return null;
}
ImmutableList.Builder<NamedExpression> newOutput = ImmutableList.builder();
for (int i = 0; i < agg.getOutputExpressions().size(); i++) {
NamedExpression expr = agg.getOutputExpressions().get(i);
if (expr instanceof Alias && expr.child(0) instanceof AggregateFunction) {
AggregateFunction f = (AggregateFunction) expr.child(0);
if (f instanceof Min || f instanceof Max) {
newOutput.add(new Alias(expr.getExprId(), f.child(0), expr.getName()));
} else {
throw new AnalysisException("Unexpected aggregate function: " + f);
}
} else {
newOutput.add(expr);
}
}
if (agg.getGroupByExpressions().isEmpty()) {
LogicalAggregate newAgg = new LogicalAggregate<>(agg.getGroupByExpressions(),
agg.getOutputExpressions(), new LogicalLimit(1, 0, LimitPhase.ORIGIN,
new LogicalProject<>(newOutput.build(), agg.child())));
return newAgg;
} else {
ImmutableList.Builder<NamedExpression> childOutput =
ImmutableList.builderWithExpectedSize(agg.getGroupByExpressions().size());
for (Expression expr : agg.getGroupByExpressions()) {
childOutput.add((NamedExpression) expr);
}
return new LogicalProject<>(newOutput.build(),
new LogicalAggregate<>(agg.getGroupByExpressions(), childOutput.build(), agg.child()));
}
}).toRule(RuleType.REDUCE_AGGREGATE_CHILD_OUTPUT_ROWS);
}
}