SemiJoinCommute.java

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package org.apache.doris.nereids.rules.rewrite;

import org.apache.doris.nereids.rules.Rule;
import org.apache.doris.nereids.rules.RuleType;
import org.apache.doris.nereids.trees.plans.logical.LogicalJoin;
import org.apache.doris.qe.ConnectContext;

/**
 * RightSemiJoin -> LeftSemiJoin
 * RightAntiJoin -> LeftAntiJoin
 * RightOuterJoin -> LeftOuterJoin
 */
public class SemiJoinCommute extends OneRewriteRuleFactory {
    @Override
    public Rule build() {
        return logicalJoin()
                .when(join -> join.getJoinType().isRightSemiOrAntiJoin() || join.getJoinType().isRightOuterJoin())
                .whenNot(join -> ConnectContext.get().getSessionVariable().isDisableJoinReorder())
                .whenNot(join -> join.isLeadingJoin())
                .whenNot(LogicalJoin::hasDistributeHint)
                .then(join -> join.withTypeChildren(join.getJoinType().swap(), join.right(), join.left(), null))
                .toRule(RuleType.LOGICAL_SEMI_JOIN_COMMUTE);
    }
}