com.hazelcast.org.apache.calcite.rel.rules.AggregateJoinJoinRemoveRule Maven / Gradle / Ivy
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* 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 com.hazelcast.com.liance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.com.hazelcast.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 com.hazelcast.org.apache.calcite.rel.rules;
import com.hazelcast.org.apache.calcite.plan.RelOptRule;
import com.hazelcast.org.apache.calcite.plan.RelOptRuleCall;
import com.hazelcast.org.apache.calcite.plan.RelOptUtil;
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.Join;
import com.hazelcast.org.apache.calcite.rel.core.JoinRelType;
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.logical.LogicalJoin;
import com.hazelcast.org.apache.calcite.rex.RexNode;
import com.hazelcast.org.apache.calcite.rex.RexUtil;
import com.hazelcast.org.apache.calcite.tools.RelBuilder;
import com.hazelcast.org.apache.calcite.tools.RelBuilderFactory;
import com.hazelcast.org.apache.calcite.util.ImmutableBitSet;
import com.hazelcast.org.apache.calcite.util.mapping.Mappings;
import com.hazelcast.com.google.com.hazelcast.com.on.collect.ImmutableList;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;
/**
* Planner rule that matches an {@link com.hazelcast.org.apache.calcite.rel.core.Aggregate}
* on a {@link com.hazelcast.org.apache.calcite.rel.core.Join} and removes the left input
* of the join provided that the left input is also a left join if possible.
*
* For instance,
*
*
* select distinct s.product_id, pc.product_id from
* sales as s
* left join product as p
* on s.product_id = p.product_id
* left join product_class pc
* on s.product_id = pc.product_id
*
* becomes
*
*
* select distinct s.product_id, pc.product_id from
* sales as s
* left join product_class pc
* on s.product_id = pc.product_id
*
*/
public class AggregateJoinJoinRemoveRule extends RelOptRule
implements TransformationRule {
public static final AggregateJoinJoinRemoveRule INSTANCE =
new AggregateJoinJoinRemoveRule(LogicalAggregate.class,
LogicalJoin.class, RelFactories.LOGICAL_BUILDER);
/** Creates an AggregateJoinJoinRemoveRule. */
public AggregateJoinJoinRemoveRule(
Class aggregateClass,
Class joinClass, RelBuilderFactory relBuilderFactory) {
super(
operand(aggregateClass,
operandJ(joinClass, null,
join -> join.getJoinType() == JoinRelType.LEFT,
operandJ(joinClass, null,
join -> join.getJoinType() == JoinRelType.LEFT, any()))),
relBuilderFactory, null);
}
@Override public void onMatch(RelOptRuleCall call) {
final Aggregate aggregate = call.rel(0);
final Join topJoin = call.rel(1);
final Join bottomJoin = call.rel(2);
int leftBottomChildSize = bottomJoin.getLeft().getRowType()
.getFieldCount();
// Check whether the aggregate uses columns in the right input of
// bottom join.
final Set allFields = RelOptUtil.getAllFields(aggregate);
if (allFields.stream().anyMatch(i -> i >= leftBottomChildSize
&& i < bottomJoin.getRowType().getFieldCount())) {
return;
}
if (aggregate.getAggCallList().stream().anyMatch(aggregateCall ->
!aggregateCall.isDistinct())) {
return;
}
// Check whether the top join uses columns in the right input of bottom join.
final List leftKeys = new ArrayList<>();
RelOptUtil.splitJoinCondition(topJoin.getLeft(), topJoin.getRight(),
topJoin.getCondition(), leftKeys, new ArrayList<>(),
new ArrayList<>());
if (leftKeys.stream().anyMatch(s -> s >= leftBottomChildSize)) {
return;
}
// Check whether left join keys in top join and bottom join are equal.
final List leftChildKeys = new ArrayList<>();
RelOptUtil.splitJoinCondition(bottomJoin.getLeft(), bottomJoin.getRight(),
bottomJoin.getCondition(), leftChildKeys, new ArrayList<>(),
new ArrayList<>());
if (!leftKeys.equals(leftChildKeys)) {
return;
}
int offset = bottomJoin.getRight().getRowType().getFieldCount();
final RelBuilder relBuilder = call.builder();
RexNode condition = RexUtil.shift(topJoin.getCondition(),
leftBottomChildSize, -offset);
RelNode join = relBuilder.push(bottomJoin.getLeft())
.push(topJoin.getRight())
.join(topJoin.getJoinType(), condition)
.build();
final Map map = new HashMap<>();
allFields.forEach(
index ->
map.put(index,
index < leftBottomChildSize ? index : index - offset));
final ImmutableBitSet groupSet = aggregate.getGroupSet().permute(map);
final ImmutableList.Builder aggCalls =
ImmutableList.builder();
final int sourceCount = aggregate.getInput().getRowType().getFieldCount();
final Mappings.TargetMapping targetMapping =
Mappings.target(map, sourceCount, sourceCount);
aggregate.getAggCallList().forEach(
aggregateCall ->
aggCalls.add(aggregateCall.transform(targetMapping)));
RelNode newAggregate = relBuilder.push(join)
.aggregate(relBuilder.groupKey(groupSet), aggCalls.build())
.build();
call.transformTo(newAggregate);
}
}