io.trino.sql.planner.iterative.rule.PruneDistinctLimitSourceColumns Maven / Gradle / Ivy
/*
* Licensed 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.trino.sql.planner.iterative.rule;
import com.google.common.collect.ImmutableSet;
import io.trino.matching.Captures;
import io.trino.matching.Pattern;
import io.trino.sql.planner.Symbol;
import io.trino.sql.planner.iterative.Rule;
import io.trino.sql.planner.plan.DistinctLimitNode;
import static io.trino.sql.planner.iterative.rule.Util.restrictChildOutputs;
import static io.trino.sql.planner.plan.Patterns.distinctLimit;
public class PruneDistinctLimitSourceColumns
implements Rule
{
private static final Pattern PATTERN = distinctLimit();
@Override
public Pattern getPattern()
{
return PATTERN;
}
@Override
public Result apply(DistinctLimitNode distinctLimit, Captures captures, Context context)
{
ImmutableSet.Builder expectedInputs = ImmutableSet.builder();
expectedInputs.addAll(distinctLimit.getOutputSymbols());
distinctLimit.getHashSymbol().ifPresent(expectedInputs::add);
return restrictChildOutputs(context.getIdAllocator(), distinctLimit, expectedInputs.build())
.map(Result::ofPlanNode)
.orElse(Result.empty());
}
}