englefly commented on code in PR #60757: URL: https://github.com/apache/doris/pull/60757#discussion_r3393679623
########## fe/fe-core/src/main/java/org/apache/doris/nereids/rules/rewrite/eageraggregation/EagerAggRewriter.java: ########## @@ -0,0 +1,625 @@ +// 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.eageraggregation; + +import org.apache.doris.nereids.rules.analysis.NormalizeAggregate; +import org.apache.doris.nereids.rules.rewrite.StatsDerive; +import org.apache.doris.nereids.stats.ExpressionEstimation; +import org.apache.doris.nereids.trees.expressions.Alias; +import org.apache.doris.nereids.trees.expressions.CaseWhen; +import org.apache.doris.nereids.trees.expressions.Cast; +import org.apache.doris.nereids.trees.expressions.Expression; +import org.apache.doris.nereids.trees.expressions.NamedExpression; +import org.apache.doris.nereids.trees.expressions.Slot; +import org.apache.doris.nereids.trees.expressions.SlotReference; +import org.apache.doris.nereids.trees.expressions.functions.agg.AggregateFunction; +import org.apache.doris.nereids.trees.expressions.functions.agg.Count; +import org.apache.doris.nereids.trees.expressions.functions.scalar.If; +import org.apache.doris.nereids.trees.plans.JoinType; +import org.apache.doris.nereids.trees.plans.Plan; +import org.apache.doris.nereids.trees.plans.logical.LogicalAggregate; +import org.apache.doris.nereids.trees.plans.logical.LogicalCatalogRelation; +import org.apache.doris.nereids.trees.plans.logical.LogicalFilter; +import org.apache.doris.nereids.trees.plans.logical.LogicalJoin; +import org.apache.doris.nereids.trees.plans.logical.LogicalProject; +import org.apache.doris.nereids.trees.plans.logical.LogicalRelation; +import org.apache.doris.nereids.trees.plans.logical.LogicalUnion; +import org.apache.doris.nereids.trees.plans.visitor.DefaultPlanRewriter; +import org.apache.doris.nereids.types.DataType; +import org.apache.doris.qe.SessionVariable; +import org.apache.doris.statistics.ColumnStatistic; +import org.apache.doris.statistics.Statistics; + +import com.google.common.collect.Lists; + +import java.util.ArrayList; +import java.util.IdentityHashMap; +import java.util.List; +import java.util.Map; +import java.util.Optional; +import java.util.Set; +import java.util.stream.Collectors; + +/** + * eager aggregation + * agg[sum(t1.A) group by t1.B] + * ->join(t1.C=t2.D) + * ->T1(A, B, C) + * ->T2(D) + * + * => + * agg[sum(x) group by t1.B] + * ->join(t1.C=t2.D) + * ->agg[sum(A) as x, group by B] + * ->T1(A, B, C) + * ->T2(D) + */ +public class EagerAggRewriter extends DefaultPlanRewriter<PushDownAggContext> { + private static final double LOWER_AGGREGATE_EFFECT_COEFFICIENT = 10000; + private static final double LOW_AGGREGATE_EFFECT_COEFFICIENT = 1000; + private static final double MEDIUM_AGGREGATE_EFFECT_COEFFICIENT = 100; + private final StatsDerive derive = new StatsDerive(false); + + @Override + public Plan visitLogicalJoin(LogicalJoin<? extends Plan, ? extends Plan> join, PushDownAggContext context) { + boolean toLeft = false; + boolean toRight = false; + boolean pushHere = false; + if (context.getAggFunctions().isEmpty()) { + // select t1.v from t1 join t2 on t1.id = t2.id group by t1.v, t2.v + // if no agg function, try to push agg to the child which contains all group keys + // TODO: consider t1.rows/(t1.id, t1.v).ndv and t2.rows/(t2.id, t2.v).ndv to determine push target + if (join.left().getOutputSet().containsAll(context.getGroupKeys())) { + toLeft = true; + } else if (join.right().getOutputSet().containsAll(context.getGroupKeys())) { + toRight = true; + } else { + pushHere = true; + } + } else { + for (AggregateFunction aggFunc : context.getAggFunctions()) { + if (join.left().getOutputSet().containsAll(aggFunc.getInputSlots())) { + toLeft = true; + } else if (join.right().getOutputSet().containsAll(aggFunc.getInputSlots())) { + toRight = true; + } else { + pushHere = true; + } Review Comment: 如果没有agg function，就按group key 来决定下推，这相当于agg function就是求 group key的distinct。 这个分支有agg function，就只需要下推agg function，下推后的group key 是join key 和 group key 与被推侧output的交集 -- This is an automated message from the Apache Git Service. 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