io.trino.sql.planner.iterative.rule.PushLimitThroughSemiJoin 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.Capture;
import io.trino.matching.Captures;
import io.trino.matching.Pattern;
import io.trino.sql.planner.iterative.Rule;
import io.trino.sql.planner.plan.LimitNode;
import io.trino.sql.planner.plan.SemiJoinNode;
import static io.trino.matching.Capture.newCapture;
import static io.trino.sql.planner.plan.Patterns.limit;
import static io.trino.sql.planner.plan.Patterns.semiJoin;
import static io.trino.sql.planner.plan.Patterns.source;
public class PushLimitThroughSemiJoin
implements Rule
{
private static final Capture CHILD = newCapture();
// Applies to both limit with ties and limit without ties.
private static final Pattern PATTERN = limit()
.with(source().matching(semiJoin().capturedAs(CHILD)));
@Override
public Pattern getPattern()
{
return PATTERN;
}
@Override
public Result apply(LimitNode parent, Captures captures, Context context)
{
SemiJoinNode semiJoinNode = captures.get(CHILD);
if (parent.isWithTies()) {
// do not push down Limit if ties depend on symbol produced by SemiJoin
if (parent.getTiesResolvingScheme().get().getOrderBy().contains(semiJoinNode.getSemiJoinOutput())) {
return Result.empty();
}
}
// Do not push down Limit with pre-sorted inputs if input ordering depends on symbol produced by SemiJoin
if (parent.getPreSortedInputs().contains(semiJoinNode.getSemiJoinOutput())) {
return Result.empty();
}
return Result.ofPlanNode(
semiJoinNode.replaceChildren(ImmutableList.of(
parent.replaceChildren(ImmutableList.of(semiJoinNode.getSource())),
semiJoinNode.getFilteringSource())));
}
}