IvmAggMinProcessor.java

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

import org.apache.doris.mtmv.ivm.IvmFailureClassifier;
import org.apache.doris.nereids.trees.expressions.Expression;
import org.apache.doris.nereids.trees.expressions.functions.agg.AggregateFunction;
import org.apache.doris.nereids.trees.expressions.functions.agg.CountAtMin;
import org.apache.doris.nereids.trees.expressions.functions.agg.Min;
import org.apache.doris.nereids.trees.expressions.functions.scalar.Least;

import java.util.List;

/** MIN-specific top-K state, delta and merge. */
class IvmAggMinProcessor extends IvmAggExtremalProcessor {
    IvmAggMinProcessor() {
        super(IvmAggFunctionKind.MIN, IvmAggStateKey.MIN_TOPK,
                IvmAggStateKey.MIN_TOPK_BOUND, "DELMIN");
    }

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

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

    @Override
    protected AggregateFunction buildExtremeCountAggregate(Expression input) {
        return new CountAtMin(input);
    }

    @Override
    protected boolean isTopKAscending() {
        return true;
    }

    @Override
    protected Expression leastOrGreatest(List<Expression> values) {
        return new Least(values.get(0),
                values.subList(1, values.size()).toArray(new Expression[0]));
    }

    @Override
    protected String fallbackMessage() {
        return IvmFailureClassifier.MIN_MAX_BOUNDARY_MSG_PREFIX
                + ": deleted row may be current MIN value";
    }
}