IvmAggMaxProcessor.java

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package org.apache.doris.mtmv.ivm.agg;

import org.apache.doris.nereids.trees.expressions.Expression;
import org.apache.doris.nereids.trees.expressions.LessThan;
import org.apache.doris.nereids.trees.expressions.Slot;
import org.apache.doris.nereids.trees.expressions.functions.agg.AggregateFunction;
import org.apache.doris.nereids.trees.expressions.functions.agg.Max;
import org.apache.doris.nereids.trees.expressions.functions.scalar.Greatest;

/** MAX-specific extreme comparisons and merge expression. */
class IvmAggMaxProcessor extends IvmAggExtremalProcessor {
    IvmAggMaxProcessor() {
        super(IvmAggFunctionKind.MAX, "DELMAX");
    }

    @Override
    public boolean supportsOriginalFunction(AggregateFunction function) {
        return function instanceof Max;
    }

    @Override
    protected Expression buildExtremeAggregate(Expression input) {
        return new Max(input);
    }

    @Override
    protected Expression deletedExtremeKeepsOldValueValid(Expression deltaDeletedExtreme, Slot oldExtreme) {
        return new LessThan(deltaDeletedExtreme, oldExtreme);
    }

    @Override
    protected Expression mergeOldAndInsertedExtreme(Slot oldExtreme, Expression deltaInsertExtreme) {
        return new Greatest(oldExtreme, deltaInsertExtreme);
    }

    @Override
    protected String fallbackMessage() {
        return "IVM: deleted row may be current MAX value, fallback to COMPLETE";
    }
}