io.trino.sql.planner.iterative.rule.EvaluateEmptyIntersect 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.ImmutableList;
import io.trino.matching.Captures;
import io.trino.matching.Pattern;
import io.trino.sql.planner.iterative.Rule;
import io.trino.sql.planner.plan.IntersectNode;
import io.trino.sql.planner.plan.ValuesNode;
import static io.trino.sql.planner.optimizations.QueryCardinalityUtil.isEmpty;
import static io.trino.sql.planner.plan.Patterns.intersect;
/**
* Converts an Intersect node with at least one empty branch to an empty Values node.
*/
public class EvaluateEmptyIntersect
implements Rule
{
private static final Pattern PATTERN = intersect();
@Override
public Pattern getPattern()
{
return PATTERN;
}
@Override
public Result apply(IntersectNode node, Captures captures, Context context)
{
boolean hasEmptyBranches = node.getSources().stream().anyMatch(source -> isEmpty(source, context.getLookup()));
if (hasEmptyBranches) {
return Result.ofPlanNode(new ValuesNode(node.getId(), node.getOutputSymbols(), ImmutableList.of()));
}
return Result.empty();
}
}