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Replace our AggregateValuesRule with Calcite's. (#3845)

This commit is contained in:
Gian Merlino 2017-01-12 13:51:50 -08:00 committed by Himanshu
parent 31bea380eb
commit b0232b4e40
2 changed files with 1 additions and 98 deletions
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98
sql/src/main/java/io/druid/sql/calcite/planner/AggregateValuesRule.java
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@ -1,98 +0,0 @@
/*
* Licensed to Metamarkets Group Inc. (Metamarkets) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. Metamarkets 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 io.druid.sql.calcite.planner;
import com.google.common.base.Predicates;
import com.google.common.collect.ImmutableList;
import org.apache.calcite.plan.RelOptRule;
import org.apache.calcite.plan.RelOptRuleCall;
import org.apache.calcite.rel.core.Aggregate;
import org.apache.calcite.rel.core.AggregateCall;
import org.apache.calcite.rel.core.Values;
import org.apache.calcite.rel.logical.LogicalValues;
import org.apache.calcite.rex.RexBuilder;
import org.apache.calcite.rex.RexLiteral;
import java.math.BigDecimal;
/**
* Rule that applies Aggregate to Values. Currently only applies to empty Values.
*
* This is still useful because PruneEmptyRules doesn't handle Aggregate, which is in turn because
* Aggregate of empty relations need some special handling: a single row will be generated, where
* each column's value depends on the specific aggregate calls (e.g. COUNT is 0, SUM is NULL).
* Sample query where this matters: <code>SELECT COUNT(*) FROM s.foo WHERE 1 = 0</code>.
*
* Can be replaced by AggregateValuesRule in Calcite 1.11.0, when released.
*/
public class AggregateValuesRule extends RelOptRule
{
public static final AggregateValuesRule INSTANCE = new AggregateValuesRule();
private AggregateValuesRule()
{
super(
operand(Aggregate.class, null, Predicates.not(Aggregate.IS_NOT_GRAND_TOTAL),
operand(Values.class, null, Values.IS_EMPTY, none())
)
);
}
@Override
public void onMatch(RelOptRuleCall call)
{
final Aggregate aggregate = call.rel(0);
final Values values = call.rel(1);
final ImmutableList.Builder<RexLiteral> literals = ImmutableList.builder();
final RexBuilder rexBuilder = call.builder().getRexBuilder();
for (final AggregateCall aggregateCall : aggregate.getAggCallList()) {
switch (aggregateCall.getAggregation().getKind()) {
case COUNT:
case SUM0:
literals.add((RexLiteral) rexBuilder.makeLiteral(
BigDecimal.ZERO, aggregateCall.getType(), false));
break;
case MIN:
case MAX:
case SUM:
literals.add(rexBuilder.constantNull());
break;
default:
// Unknown what this aggregate call should do on empty Values. Bail out to be safe.
return;
}
}
call.transformTo(
LogicalValues.create(
values.getCluster(),
aggregate.getRowType(),
ImmutableList.of(literals.build())
)
);
// New plan is absolutely better than old plan.
call.getPlanner().setImportance(aggregate, 0.0);
}
}

1
sql/src/main/java/io/druid/sql/calcite/planner/Rules.java
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@ -35,6 +35,7 @@ import org.apache.calcite.rel.rules.AggregateProjectMergeRule;
import org.apache.calcite.rel.rules.AggregateProjectPullUpConstantsRule;
import org.apache.calcite.rel.rules.AggregateRemoveRule;
import org.apache.calcite.rel.rules.AggregateStarTableRule;
import org.apache.calcite.rel.rules.AggregateValuesRule;
import org.apache.calcite.rel.rules.CalcRemoveRule;
import org.apache.calcite.rel.rules.DateRangeRules;
import org.apache.calcite.rel.rules.FilterAggregateTransposeRule;