lancelly commented on code in PR #14148: URL: https://github.com/apache/iotdb/pull/14148#discussion_r1862887530
########## iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/relational/planner/optimizations/QueryCardinalityUtil.java: ########## @@ -0,0 +1,208 @@ +/* + * 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.iotdb.db.queryengine.plan.relational.planner.optimizations; + +import org.apache.iotdb.db.queryengine.plan.planner.plan.node.PlanNode; +import org.apache.iotdb.db.queryengine.plan.planner.plan.node.PlanVisitor; +import org.apache.iotdb.db.queryengine.plan.planner.plan.node.process.ExchangeNode; +import org.apache.iotdb.db.queryengine.plan.relational.planner.iterative.GroupReference; +import org.apache.iotdb.db.queryengine.plan.relational.planner.iterative.Lookup; +import org.apache.iotdb.db.queryengine.plan.relational.planner.node.AggregationNode; +import org.apache.iotdb.db.queryengine.plan.relational.planner.node.EnforceSingleRowNode; +import org.apache.iotdb.db.queryengine.plan.relational.planner.node.FilterNode; +import org.apache.iotdb.db.queryengine.plan.relational.planner.node.LimitNode; +import org.apache.iotdb.db.queryengine.plan.relational.planner.node.OffsetNode; +import org.apache.iotdb.db.queryengine.plan.relational.planner.node.ProjectNode; + +import com.google.common.collect.Range; + +import static com.google.common.collect.Iterables.getOnlyElement; +import static java.lang.Math.max; +import static java.lang.Math.min; +import static java.util.Objects.requireNonNull; +import static org.apache.iotdb.db.queryengine.plan.relational.planner.iterative.Lookup.noLookup; + +public final class QueryCardinalityUtil { + private QueryCardinalityUtil() {} + + public static boolean isScalar(PlanNode node) { + return isScalar(node, noLookup()); + } + + public static boolean isScalar(PlanNode node, Lookup lookup) { + return extractCardinality(node, lookup).isScalar(); + } + + public static boolean isAtMostScalar(PlanNode node) { + return isAtMostScalar(node, noLookup()); + } + + public static boolean isAtMostScalar(PlanNode node, Lookup lookup) { + return isAtMost(node, lookup, 1L); + } + + public static boolean isAtMost(PlanNode node, Lookup lookup, long maxCardinality) { + return extractCardinality(node, lookup).isAtMost(maxCardinality); + } + + public static boolean isAtLeastScalar(PlanNode node, Lookup lookup) { + return isAtLeast(node, lookup, 1L); + } + + public static boolean isAtLeast(PlanNode node, Lookup lookup, long minCardinality) { + return extractCardinality(node, lookup).isAtLeast(minCardinality); + } + + public static boolean isEmpty(PlanNode node, Lookup lookup) { + return isAtMost(node, lookup, 0); + } + + public static Cardinality extractCardinality(PlanNode node) { + return extractCardinality(node, noLookup()); + } + + public static Cardinality extractCardinality(PlanNode node, Lookup lookup) { + return new Cardinality(node.accept(new CardinalityExtractorPlanVisitor(lookup), null)); + } + + private static final class CardinalityExtractorPlanVisitor + extends PlanVisitor<Range<Long>, Void> { + private final Lookup lookup; + + public CardinalityExtractorPlanVisitor(Lookup lookup) { + this.lookup = requireNonNull(lookup, "lookup is null"); + } + + @Override + public Range<Long> visitPlan(PlanNode node, Void context) { + return Range.atLeast(0L); + } + + @Override + public Range<Long> visitGroupReference(GroupReference node, Void context) { + return lookup.resolve(node).accept(this, context); + } + + @Override + public Range<Long> visitEnforceSingleRow(EnforceSingleRowNode node, Void context) { + return Range.singleton(1L); + } + + @Override + public Range<Long> visitAggregation(AggregationNode node, Void context) { + if (node.hasSingleGlobalAggregation()) { + // only single default aggregation which will produce exactly single row + return Range.singleton(1L); + } + + Range<Long> sourceCardinalityRange = node.getChild().accept(this, null); + + long lower; + if (node.hasDefaultOutput() || sourceCardinalityRange.lowerEndpoint() > 0) { + lower = 1; + } else { + lower = 0; + } + + if (sourceCardinalityRange.hasUpperBound()) { + long upper = Math.max(lower, sourceCardinalityRange.upperEndpoint()); + return Range.closed(lower, upper); + } + + return Range.atLeast(lower); + } + + @Override + public Range<Long> visitExchange(ExchangeNode node, Void context) { + if (node.getChildren().size() == 1) { + return getOnlyElement(node.getChildren()).accept(this, null); + } + return Range.atLeast(0L); + } + + @Override + public Range<Long> visitProject(ProjectNode node, Void context) { + return node.getChild().accept(this, null); + } + + @Override + public Range<Long> visitFilter(FilterNode node, Void context) { + Range<Long> sourceCardinalityRange = node.getChild().accept(this, null); + if (sourceCardinalityRange.hasUpperBound()) { + return Range.closed(0L, sourceCardinalityRange.upperEndpoint()); + } + return Range.atLeast(0L); + } + + // @Override + // public Range<Long> visitValues(ValuesNode node, Void context) + // { + // return Range.singleton((long) node.getRowCount()); + // } + + @Override + public Range<Long> visitOffset(OffsetNode node, Void context) { + Range<Long> sourceCardinalityRange = node.getChild().accept(this, null); + + long lower = max(sourceCardinalityRange.lowerEndpoint() - node.getCount(), 0L); + + if (sourceCardinalityRange.hasUpperBound()) { + return Range.closed( + lower, max(sourceCardinalityRange.upperEndpoint() - node.getCount(), 0L)); + } + return Range.atLeast(lower); + } + + @Override + public Range<Long> visitLimit(LimitNode node, Void context) { + if (node.isWithTies()) { + Range<Long> sourceCardinalityRange = node.getChild().accept(this, null); + long lower = min(node.getCount(), sourceCardinalityRange.lowerEndpoint()); + if (sourceCardinalityRange.hasUpperBound()) { + return Range.closed(lower, sourceCardinalityRange.upperEndpoint()); + } + return Range.atLeast(lower); + } + + return applyLimit(node.getChild(), node.getCount()); + } + + // @Override + // public Range<Long> visitTopN(TopNNode node, Void context) + // { + // return applyLimit(node.getSource(), node.getCount()); + // } Review Comment: Fixed. -- This is an automated message from the Apache Git Service. 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