morrySnow commented on code in PR #32188: URL: https://github.com/apache/doris/pull/32188#discussion_r1546024282
########## fe/fe-core/src/main/java/org/apache/doris/nereids/rules/rewrite/ReduceAggregateChildOutputRows.java: ########## @@ -0,0 +1,89 @@ +// Licensed to the Apache Software Foundation (ASF) under one +// or more contributor license agreements. See the NOTICE file +// distributed with this work for additional information +// regarding copyright ownership. The ASF licenses this file +// to you 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 org.apache.doris.nereids.rules.rewrite; + +import org.apache.doris.nereids.exceptions.AnalysisException; +import org.apache.doris.nereids.rules.Rule; +import org.apache.doris.nereids.rules.RuleType; +import org.apache.doris.nereids.trees.expressions.Alias; +import org.apache.doris.nereids.trees.expressions.Expression; +import org.apache.doris.nereids.trees.expressions.NamedExpression; +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.agg.Min; +import org.apache.doris.nereids.trees.plans.LimitPhase; +import org.apache.doris.nereids.trees.plans.logical.LogicalAggregate; +import org.apache.doris.nereids.trees.plans.logical.LogicalLimit; +import org.apache.doris.nereids.trees.plans.logical.LogicalProject; + +import com.google.common.collect.ImmutableList; + +import java.util.Set; + +/** ReduceAggregateChildOutputRows + * with group by: + * select max(1) from t1 group by c1; -> select 1 from (select c1 from t1 group by c1); + * without group by: + * select max(1) from t1; -> select max(1) from (select 1 from t1 limit 1) tmp; + * */ +public class ReduceAggregateChildOutputRows extends OneRewriteRuleFactory { + @Override + public Rule build() { + return logicalAggregate().then(agg -> { + Set<AggregateFunction> aggFunctions = agg.getAggregateFunctions(); + // check whether we have aggregate(constant) in all aggregateFunctions + if (!(agg.child() instanceof LogicalLimit) Review Comment: better to check limit is 1? -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: commits-unsubscr...@doris.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: commits-unsubscr...@doris.apache.org For additional commands, e-mail: commits-h...@doris.apache.org
