Kikyou1997 commented on code in PR #19934: URL: https://github.com/apache/doris/pull/19934#discussion_r1206637032
########## fe/fe-core/src/main/java/org/apache/doris/nereids/rules/rewrite/logical/CTEProducerRewrite.java: ########## @@ -0,0 +1,122 @@ +// 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.logical; + +import org.apache.doris.nereids.CascadesContext; +import org.apache.doris.nereids.jobs.batch.NereidsRewriter; +import org.apache.doris.nereids.rules.Rule; +import org.apache.doris.nereids.rules.RuleType; +import org.apache.doris.nereids.rules.rewrite.OneRewriteRuleFactory; +import org.apache.doris.nereids.trees.expressions.Expression; +import org.apache.doris.nereids.trees.expressions.SlotReference; +import org.apache.doris.nereids.trees.plans.Plan; +import org.apache.doris.nereids.trees.plans.logical.LogicalCTEConsumer; +import org.apache.doris.nereids.trees.plans.logical.LogicalCTEProducer; +import org.apache.doris.nereids.trees.plans.logical.LogicalFilter; +import org.apache.doris.nereids.trees.plans.logical.LogicalPlan; +import org.apache.doris.nereids.trees.plans.logical.LogicalProject; +import org.apache.doris.nereids.util.ExpressionUtils; + +import com.google.common.collect.ImmutableList; +import com.google.common.collect.ImmutableSet; +import org.apache.commons.collections.CollectionUtils; + +import java.util.ArrayList; +import java.util.HashSet; +import java.util.Map.Entry; +import java.util.Set; +import java.util.stream.Collectors; + +/** + * Rewrite CTE Producer recursively. + */ +public class CTEProducerRewrite extends OneRewriteRuleFactory { + + @Override + public Rule build() { + return logicalCTEProducer().when(p -> !p.isRewritten()).thenApply(ctx -> { + LogicalCTEProducer<? extends Plan> cteProducer = ctx.root; + Set<Expression> projects = ctx.cascadesContext.findProjectForProducer(cteProducer.getCteId()); + LogicalPlan child = tryToConstructFilter(ctx.cascadesContext, cteProducer.getCteId(), + (LogicalPlan) ctx.root.child()); + if (CollectionUtils.isNotEmpty(projects) + && ctx.cascadesContext.couldPruneColumnOnProducer(cteProducer.getCteId())) { + child = new LogicalProject(ImmutableList.copyOf(projects), child); + } + CascadesContext rewrittenCtx = ctx.cascadesContext.forkForCTEProducer(child); + NereidsRewriter rewriter = new NereidsRewriter(rewrittenCtx); + rewriter.execute(); + return cteProducer.withChildrenAndProjects(ImmutableList.of(rewrittenCtx.getRewritePlan()), + new ArrayList<>(child.getOutput()), true); + }).toRule(RuleType.CTE_PRODUCER_REWRITE); + } + + /* + * An expression can only be pushed down if it has filter expressions on all consumers that reference the slot. + * For example, let's assume a producer has two consumers, consumer1 and consumer2: + * + * filter(a > 5 and b < 1) -> consumer1 + * filter(a < 8) -> consumer2 + * + * In this case, the only expression that can be pushed down to the producer is filter(a > 5 or a < 8). + */ + private LogicalPlan tryToConstructFilter(CascadesContext cascadesContext, int cteId, LogicalPlan child) { Review Comment: Ok, I'll do it later -- 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
