PartitionPrunablePredicate.java

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

import org.apache.doris.nereids.trees.expressions.Expression;
import org.apache.doris.nereids.trees.expressions.Slot;

import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableSet;

import java.util.List;
import java.util.Objects;
import java.util.Set;

/**
 * Records that, on the scan whose partition list equals {@link
 * #selectedPartitionIds}, the {@link #prunableConjuncts} are guaranteed to
 * evaluate to TRUE for every surviving row.
 *
 * <p>The predicate is registered by {@link
 * org.apache.doris.nereids.rules.rewrite.PruneOlapScanPartition} but kept in
 * the logical filter during cascades. The actual removal happens later in
 * {@link org.apache.doris.nereids.processor.post.PrunePartitionPredicate} so
 * that materialized-view rewrite still sees the original predicates. Keeping
 * the predicate in the plan avoids the wrong-result problem in which the MV
 * view-predicate happens to cover the remaining conjuncts after the partition
 * predicate has been silently dropped.
 *
 * <p>The predicate lives on the scan itself (see {@code LogicalOlapScan} and
 * {@code PhysicalOlapScan}) so we no longer need to match it back to its scan
 * via a table identifier. Because rewrites between recording and removal may
 * rebuild the scan with fresh slot ids, {@link #snapshotPartitionSlots}
 * captures the slots that appear in the recorded conjuncts. The post-processor
 * maps them onto the actual scan's output slots by column name before
 * performing the conjunct removal.
 */
public class PartitionPrunablePredicate {
    private final Set<Long> selectedPartitionIds;
    private final List<Slot> snapshotPartitionSlots;
    private final Set<Expression> prunableConjuncts;

    public PartitionPrunablePredicate(Set<Long> selectedPartitionIds,
            List<Slot> snapshotPartitionSlots,
            Set<Expression> prunableConjuncts) {
        this.selectedPartitionIds = ImmutableSet.copyOf(selectedPartitionIds);
        this.snapshotPartitionSlots = ImmutableList.copyOf(snapshotPartitionSlots);
        this.prunableConjuncts = ImmutableSet.copyOf(prunableConjuncts);
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) {
            return true;
        }
        if (o == null || getClass() != o.getClass()) {
            return false;
        }
        PartitionPrunablePredicate that = (PartitionPrunablePredicate) o;
        return selectedPartitionIds.equals(that.selectedPartitionIds)
                && snapshotPartitionSlots.equals(that.snapshotPartitionSlots)
                && prunableConjuncts.equals(that.prunableConjuncts);
    }

    @Override
    public int hashCode() {
        return Objects.hash(selectedPartitionIds, snapshotPartitionSlots, prunableConjuncts);
    }

    public Set<Long> getSelectedPartitionIds() {
        return selectedPartitionIds;
    }

    public List<Slot> getSnapshotPartitionSlots() {
        return snapshotPartitionSlots;
    }

    public Set<Expression> getPrunableConjuncts() {
        return prunableConjuncts;
    }
}