| // 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.impala.planner; |
| |
| import org.apache.impala.analysis.Analyzer; |
| import org.apache.impala.analysis.CollectionTableRef; |
| import org.apache.impala.analysis.Expr; |
| import org.apache.impala.common.ImpalaException; |
| import org.apache.impala.thrift.TExplainLevel; |
| import org.apache.impala.thrift.TPlanNode; |
| import org.apache.impala.thrift.TPlanNodeType; |
| import org.apache.impala.thrift.TQueryOptions; |
| import org.apache.impala.thrift.TUnnestNode; |
| import com.google.common.base.Joiner; |
| import com.google.common.base.Preconditions; |
| |
| /** |
| * An UnnestNode scans over a collection materialized in memory, and returns |
| * one row per item in the collection. |
| * An UnnestNode can only appear in the plan tree of a SubplanNode. |
| */ |
| public class UnnestNode extends PlanNode { |
| private final SubplanNode containingSubplanNode_; |
| private final CollectionTableRef tblRef_; |
| private final Expr collectionExpr_; |
| |
| public UnnestNode(PlanNodeId id, SubplanNode containingSubplanNode, |
| CollectionTableRef tblRef) { |
| super(id, tblRef.getDesc().getId().asList(), "UNNEST"); |
| containingSubplanNode_ = containingSubplanNode; |
| tblRef_ = tblRef; |
| collectionExpr_ = tblRef_.getCollectionExpr(); |
| // Assume the collection expr has been fully resolved in analysis. |
| Preconditions.checkState( |
| collectionExpr_.isBoundByTupleIds(containingSubplanNode.getChild(0).tupleIds_)); |
| } |
| |
| @Override |
| public void init(Analyzer analyzer) throws ImpalaException { |
| // Do not assign binding predicates or predicates for enforcing slot equivalences |
| // because they must have been assigned in the scan node materializing the |
| // collection-typed slot. |
| super.init(analyzer); |
| conjuncts_ = orderConjunctsByCost(conjuncts_); |
| |
| // Unnest is like a scan and must materialize the slots of its conjuncts. |
| analyzer.materializeSlots(conjuncts_); |
| computeMemLayout(analyzer); |
| } |
| |
| @Override |
| public void computeStats(Analyzer analyzer) { |
| super.computeStats(analyzer); |
| cardinality_ = PlannerContext.AVG_COLLECTION_SIZE; |
| // The containing SubplanNode has not yet been initialized, so get the number |
| // of nodes from the SubplanNode's input. |
| numNodes_ = containingSubplanNode_.getChild(0).getNumNodes(); |
| numInstances_ = containingSubplanNode_.getChild(0).getNumInstances(); |
| cardinality_ = capCardinalityAtLimit(cardinality_); |
| } |
| |
| @Override |
| public void computeNodeResourceProfile(TQueryOptions queryOptions) { |
| // TODO: add an estimate |
| nodeResourceProfile_ = ResourceProfile.noReservation(0); |
| } |
| |
| @Override |
| protected String getNodeExplainString(String prefix, String detailPrefix, |
| TExplainLevel detailLevel) { |
| StringBuilder output = new StringBuilder(); |
| output.append(String.format("%s%s [%s]\n", prefix, getDisplayLabel(), |
| getDisplayLabelDetail())); |
| if (detailLevel.ordinal() >= TExplainLevel.EXTENDED.ordinal()) { |
| output.append(String.format( |
| "%sparent-subplan=%s\n", detailPrefix, containingSubplanNode_.getId())); |
| } |
| if (detailLevel.ordinal() >= TExplainLevel.STANDARD.ordinal()) { |
| if (!conjuncts_.isEmpty()) { |
| output.append(detailPrefix |
| + "predicates: " + Expr.getExplainString(conjuncts_, detailLevel) + "\n"); |
| } |
| } |
| return output.toString(); |
| } |
| |
| @Override |
| protected String getDisplayLabelDetail() { |
| StringBuilder strBuilder = new StringBuilder(); |
| strBuilder.append(Joiner.on(".").join(tblRef_.getPath())); |
| if (tblRef_.hasExplicitAlias()) strBuilder.append(" " + tblRef_.getExplicitAlias()); |
| return strBuilder.toString(); |
| } |
| |
| @Override |
| protected void toThrift(TPlanNode msg) { |
| msg.node_type = TPlanNodeType.UNNEST_NODE; |
| msg.setUnnest_node(new TUnnestNode(collectionExpr_.treeToThrift())); |
| } |
| } |