com.hazelcast.org.apache.calcite.rel.rules.AggregateRemoveRule Maven / Gradle / Ivy
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* 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
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* distributed under the License is distributed on an "AS IS" BASIS,
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package com.hazelcast.org.apache.calcite.rel.rules;
import com.hazelcast.org.apache.calcite.plan.RelOptRuleCall;
import com.hazelcast.org.apache.calcite.plan.RelRule;
import com.hazelcast.org.apache.calcite.rel.RelNode;
import com.hazelcast.org.apache.calcite.rel.core.Aggregate;
import com.hazelcast.org.apache.calcite.rel.core.AggregateCall;
import com.hazelcast.org.apache.calcite.rel.core.RelFactories;
import com.hazelcast.org.apache.calcite.rel.logical.LogicalAggregate;
import com.hazelcast.org.apache.calcite.rel.metadata.RelMetadataQuery;
import com.hazelcast.org.apache.calcite.rex.RexBuilder;
import com.hazelcast.org.apache.calcite.rex.RexNode;
import com.hazelcast.org.apache.calcite.runtime.SqlFunctions;
import com.hazelcast.org.apache.calcite.sql.SqlAggFunction;
import com.hazelcast.org.apache.calcite.sql.SqlKind;
import com.hazelcast.org.apache.calcite.sql.SqlSplittableAggFunction;
import com.hazelcast.org.apache.calcite.tools.RelBuilder;
import com.hazelcast.org.apache.calcite.tools.RelBuilderFactory;
import org.immutables.value.Value;
import java.util.ArrayList;
import java.util.List;
/**
* Planner rule that removes
* a {@link com.hazelcast.org.apache.calcite.rel.core.Aggregate}
* if it computes no aggregate functions
* (that is, it is implementing {@code SELECT DISTINCT}),
* or all the aggregate functions are splittable,
* and the underlying relational expression is already distinct.
*
* @see CoreRules#AGGREGATE_REMOVE
*/
@Value.Enclosing
public class AggregateRemoveRule
extends RelRule
implements SubstitutionRule {
/** Creates an AggregateRemoveRule. */
protected AggregateRemoveRule(Config config) {
super(config);
}
@Deprecated // to be removed before 2.0
public AggregateRemoveRule(Class extends Aggregate> aggregateClass) {
this(aggregateClass, RelFactories.LOGICAL_BUILDER);
}
@Deprecated // to be removed before 2.0
public AggregateRemoveRule(Class extends Aggregate> aggregateClass,
RelBuilderFactory relBuilderFactory) {
this(Config.DEFAULT
.withRelBuilderFactory(relBuilderFactory)
.as(Config.class)
.withOperandFor(aggregateClass));
}
private static boolean isAggregateSupported(Aggregate aggregate) {
if (aggregate.getGroupType() != Aggregate.Group.SIMPLE
|| aggregate.getGroupCount() == 0) {
return false;
}
// If any aggregate functions do not support splitting, bail out.
for (AggregateCall aggregateCall : aggregate.getAggCallList()) {
if (aggregateCall.filterArg >= 0
|| !aggregateCall.getAggregation()
.maybeUnwrap(SqlSplittableAggFunction.class).isPresent()) {
return false;
}
}
return true;
}
//~ Methods ----------------------------------------------------------------
@Override public void onMatch(RelOptRuleCall call) {
final Aggregate aggregate = call.rel(0);
final RelNode input = aggregate.getInput();
final RelMetadataQuery mq = call.getMetadataQuery();
if (!SqlFunctions.isTrue(mq.areColumnsUnique(input, aggregate.getGroupSet()))) {
return;
}
final RelBuilder relBuilder = call.builder();
final RexBuilder rexBuilder = relBuilder.getRexBuilder();
final List projects = new ArrayList<>();
for (AggregateCall aggCall : aggregate.getAggCallList()) {
final SqlAggFunction aggregation = aggCall.getAggregation();
if (aggregation.getKind() == SqlKind.SUM0) {
// Bail out for SUM0 to avoid potential infinite rule matching,
// because it may be generated by transforming SUM aggregate
// function to SUM0 and COUNT.
return;
}
final SqlSplittableAggFunction splitter =
aggregation.unwrapOrThrow(SqlSplittableAggFunction.class);
final RexNode singleton =
splitter.singleton(rexBuilder, input.getRowType(), aggCall);
final RexNode cast =
rexBuilder.ensureType(aggCall.type, singleton, false);
projects.add(cast);
}
final RelNode newInput = convert(input, aggregate.getTraitSet().simplify());
relBuilder.push(newInput);
if (!projects.isEmpty()) {
projects.addAll(0, relBuilder.fields(aggregate.getGroupSet()));
relBuilder.project(projects);
} else if (newInput.getRowType().getFieldCount()
> aggregate.getRowType().getFieldCount()) {
// If aggregate was projecting a subset of columns, and there were no
// aggregate functions, add a project for the same effect.
relBuilder.project(relBuilder.fields(aggregate.getGroupSet()));
}
call.getPlanner().prune(aggregate);
call.transformTo(relBuilder.build());
}
/** Rule configuration. */
@Value.Immutable
public interface Config extends RelRule.Config {
Config DEFAULT = ImmutableAggregateRemoveRule.Config.of()
.withRelBuilderFactory(RelFactories.LOGICAL_BUILDER)
.withOperandFor(LogicalAggregate.class);
@Override default AggregateRemoveRule toRule() {
return new AggregateRemoveRule(this);
}
/** Defines an operand tree for the given classes. */
default Config withOperandFor(Class extends Aggregate> aggregateClass) {
return withOperandSupplier(b ->
b.operand(aggregateClass)
.predicate(AggregateRemoveRule::isAggregateSupported)
.anyInputs())
.as(Config.class);
}
}
}
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