io.trino.cost.SampleStatsRule Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of trino-main Show documentation

Trino - Engine

There is a newer version: 468

/*
 * 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.Session;
import io.trino.matching.Pattern;
import io.trino.sql.planner.TypeProvider;
import io.trino.sql.planner.iterative.Lookup;
import io.trino.sql.planner.plan.SampleNode;

import java.util.Optional;

import static io.trino.sql.planner.plan.Patterns.sample;

public class SampleStatsRule
        extends SimpleStatsRule
{
    private static final Pattern PATTERN = sample();

    public SampleStatsRule(StatsNormalizer normalizer)
    {
        super(normalizer);
    }

    @Override
    public Pattern getPattern()
    {
        return PATTERN;
    }

    @Override
    protected Optional doCalculate(SampleNode node, StatsProvider statsProvider, Lookup lookup, Session session, TypeProvider types, TableStatsProvider tableStatsProvider)
    {
        PlanNodeStatsEstimate sourceStats = statsProvider.getStats(node.getSource());
        PlanNodeStatsEstimate calculatedStats = sourceStats.mapOutputRowCount(outputRowCount -> outputRowCount * node.getSampleRatio());
        return Optional.of(calculatedStats);
    }
}