org.apache.hadoop.hive.ql.optimizer.pcr.PartitionConditionRemover Maven / Gradle / Ivy
/**
* 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.hadoop.hive.ql.optimizer.pcr;
import java.util.ArrayList;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.hive.ql.exec.Operator;
import org.apache.hadoop.hive.ql.exec.FilterOperator;
import org.apache.hadoop.hive.ql.exec.TableScanOperator;
import org.apache.hadoop.hive.ql.lib.DefaultGraphWalker;
import org.apache.hadoop.hive.ql.lib.DefaultRuleDispatcher;
import org.apache.hadoop.hive.ql.lib.Dispatcher;
import org.apache.hadoop.hive.ql.lib.GraphWalker;
import org.apache.hadoop.hive.ql.lib.Node;
import org.apache.hadoop.hive.ql.lib.NodeProcessor;
import org.apache.hadoop.hive.ql.lib.Rule;
import org.apache.hadoop.hive.ql.lib.RuleRegExp;
import org.apache.hadoop.hive.ql.optimizer.Transform;
import org.apache.hadoop.hive.ql.parse.ParseContext;
import org.apache.hadoop.hive.ql.parse.SemanticException;
/**
* The transformation step that does partition condition remover.
*
*/
public class PartitionConditionRemover implements Transform {
// The log
private static final Log LOG = LogFactory
.getLog("hive.ql.optimizer.pcr.PartitionConditionRemover");
/*
* (non-Javadoc)
*
* @see
* org.apache.hadoop.hive.ql.optimizer.Transform#transform(org.apache.hadoop
* .hive.ql.parse.ParseContext)
*/
@Override
public ParseContext transform(ParseContext pctx) throws SemanticException {
// create a the context for walking operators
List opToRemove =
new ArrayList();
PcrOpWalkerCtx opWalkerCtx = new PcrOpWalkerCtx(pctx, opToRemove);
Map opRules = new LinkedHashMap();
opRules.put(new RuleRegExp("R1",
"(" + TableScanOperator.getOperatorName() + "%"
+ FilterOperator.getOperatorName() + "%)|("
+ TableScanOperator.getOperatorName() + "%"
+ FilterOperator.getOperatorName() + "%"
+ FilterOperator.getOperatorName() + "%)"),
PcrOpProcFactory.getFilterProc());
// The dispatcher fires the processor corresponding to the closest matching
// rule and passes the context along
Dispatcher disp = new DefaultRuleDispatcher(PcrOpProcFactory.getDefaultProc(),
opRules, opWalkerCtx);
GraphWalker ogw = new DefaultGraphWalker(disp);
// Create a list of topop nodes
ArrayList topNodes = new ArrayList();
topNodes.addAll(pctx.getTopOps().values());
ogw.startWalking(topNodes, null);
for (PcrOpWalkerCtx.OpToDeleteInfo entry : opToRemove) {
entry.getParent().removeChildAndAdoptItsChildren(entry.getOperator());
}
return pctx;
}
}