io.trino.cost.EnforceSingleRowStatsRule 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.cost;
import io.trino.cost.StatsCalculator.Context;
import io.trino.matching.Pattern;
import io.trino.sql.planner.plan.EnforceSingleRowNode;
import java.util.Optional;
import static io.trino.sql.planner.plan.Patterns.enforceSingleRow;
public class EnforceSingleRowStatsRule
extends SimpleStatsRule
{
private static final Pattern PATTERN = enforceSingleRow();
public EnforceSingleRowStatsRule(StatsNormalizer normalizer)
{
super(normalizer);
}
@Override
public Pattern getPattern()
{
return PATTERN;
}
@Override
protected Optional doCalculate(EnforceSingleRowNode node, Context context)
{
return Optional.of(PlanNodeStatsEstimate.buildFrom(context.statsProvider().getStats(node.getSource()))
.setOutputRowCount(1)
.build());
}
}