/**
* 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;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.Stack;
import org.apache.hadoop.hive.conf.HiveConf;
import org.apache.hadoop.hive.metastore.Warehouse;
import org.apache.hadoop.hive.metastore.api.MetaException;
import org.apache.hadoop.hive.ql.DriverContext;
import org.apache.hadoop.hive.ql.ErrorMsg;
import org.apache.hadoop.hive.ql.exec.Operator;
import org.apache.hadoop.hive.ql.exec.TableScanOperator;
import org.apache.hadoop.hive.ql.exec.Task;
import org.apache.hadoop.hive.ql.exec.TaskFactory;
import org.apache.hadoop.hive.ql.io.rcfile.stats.PartialScanWork;
import org.apache.hadoop.hive.ql.lib.Node;
import org.apache.hadoop.hive.ql.lib.NodeProcessor;
import org.apache.hadoop.hive.ql.lib.NodeProcessorCtx;
import org.apache.hadoop.hive.ql.metadata.Partition;
import org.apache.hadoop.hive.ql.metadata.Table;
import org.apache.hadoop.hive.ql.optimizer.GenMRProcContext.GenMapRedCtx;
import org.apache.hadoop.hive.ql.parse.BaseSemanticAnalyzer.tableSpec;
import org.apache.hadoop.hive.ql.parse.ParseContext;
import org.apache.hadoop.hive.ql.parse.PrunedPartitionList;
import org.apache.hadoop.hive.ql.parse.QBParseInfo;
import org.apache.hadoop.hive.ql.parse.SemanticException;
import org.apache.hadoop.hive.ql.plan.MapredWork;
import org.apache.hadoop.hive.ql.plan.OperatorDesc;
import org.apache.hadoop.hive.ql.plan.StatsWork;
/**
* Processor for the rule - table scan.
*/
public class GenMRTableScan1 implements NodeProcessor {
public GenMRTableScan1() {
}
/**
* Table Sink encountered.
*
* @param nd
* the table sink operator encountered
* @param opProcCtx
* context
*/
public Object process(Node nd, Stack<Node> stack, NodeProcessorCtx opProcCtx,
Object... nodeOutputs) throws SemanticException {
TableScanOperator op = (TableScanOperator) nd;
GenMRProcContext ctx = (GenMRProcContext) opProcCtx;
ParseContext parseCtx = ctx.getParseCtx();
Map<Operator<? extends OperatorDesc>, GenMapRedCtx> mapCurrCtx = ctx.getMapCurrCtx();
// create a dummy MapReduce task
MapredWork currWork = GenMapRedUtils.getMapRedWork(parseCtx);
Task<? extends Serializable> currTask = TaskFactory.get(currWork, parseCtx.getConf());
Operator<? extends OperatorDesc> currTopOp = op;
ctx.setCurrTask(currTask);
ctx.setCurrTopOp(currTopOp);
for (String alias : parseCtx.getTopOps().keySet()) {
Operator<? extends OperatorDesc> currOp = parseCtx.getTopOps().get(alias);
if (currOp == op) {
String currAliasId = alias;
ctx.setCurrAliasId(currAliasId);
mapCurrCtx.put(op, new GenMapRedCtx(currTask, currTopOp, currAliasId));
QBParseInfo parseInfo = parseCtx.getQB().getParseInfo();
if (parseInfo.isAnalyzeCommand()) {
// ANALYZE TABLE T [PARTITION (...)] COMPUTE STATISTICS;
// The plan consists of a simple MapRedTask followed by a StatsTask.
// The MR task is just a simple TableScanOperator
StatsWork statsWork = new StatsWork(parseCtx.getQB().getParseInfo().getTableSpec());
statsWork.setAggKey(op.getConf().getStatsAggPrefix());
statsWork.setStatsReliable(
parseCtx.getConf().getBoolVar(HiveConf.ConfVars.HIVE_STATS_RELIABLE));
Task<StatsWork> statsTask = TaskFactory.get(statsWork, parseCtx.getConf());
currTask.addDependentTask(statsTask);
if (!ctx.getRootTasks().contains(currTask)) {
ctx.getRootTasks().add(currTask);
}
// ANALYZE TABLE T [PARTITION (...)] COMPUTE STATISTICS noscan;
// The plan consists of a StatsTask only.
if (parseInfo.isNoScanAnalyzeCommand()) {
statsTask.setParentTasks(null);
statsWork.setNoScanAnalyzeCommand(true);
ctx.getRootTasks().remove(currTask);
ctx.getRootTasks().add(statsTask);
}
// ANALYZE TABLE T [PARTITION (...)] COMPUTE STATISTICS partialscan;
if (parseInfo.isPartialScanAnalyzeCommand()) {
handlePartialScanCommand(op, ctx, parseCtx, currTask, parseInfo, statsWork, statsTask);
}
currWork.setGatheringStats(true);
// NOTE: here we should use the new partition predicate pushdown API to get a list of pruned list,
// and pass it to setTaskPlan as the last parameter
Set<Partition> confirmedPartns = new HashSet<Partition>();
tableSpec tblSpec = parseInfo.getTableSpec();
if (tblSpec.specType == tableSpec.SpecType.STATIC_PARTITION) {
// static partition
if (tblSpec.partHandle != null) {
confirmedPartns.add(tblSpec.partHandle);
} else {
// partial partition spec has null partHandle
assert parseInfo.isNoScanAnalyzeCommand();
confirmedPartns.addAll(tblSpec.partitions);
}
} else if (tblSpec.specType == tableSpec.SpecType.DYNAMIC_PARTITION) {
// dynamic partition
confirmedPartns.addAll(tblSpec.partitions);
}
if (confirmedPartns.size() > 0) {
Table source = parseCtx.getQB().getMetaData().getTableForAlias(alias);
PrunedPartitionList partList = new PrunedPartitionList(source, confirmedPartns,
new HashSet<Partition>(), null);
GenMapRedUtils.setTaskPlan(currAliasId, currTopOp, currWork, false, ctx, partList);
} else { // non-partitioned table
GenMapRedUtils.setTaskPlan(currAliasId, currTopOp, currWork, false, ctx);
}
}
return null;
}
}
assert false;
return null;
}
/**
* handle partial scan command.
*
* It is composed of PartialScanTask followed by StatsTask .
* @param op
* @param ctx
* @param parseCtx
* @param currTask
* @param parseInfo
* @param statsWork
* @param statsTask
* @throws SemanticException
*/
private void handlePartialScanCommand(TableScanOperator op, GenMRProcContext ctx,
ParseContext parseCtx,
Task<? extends Serializable> currTask, QBParseInfo parseInfo, StatsWork statsWork,
Task<StatsWork> statsTask) throws SemanticException {
String aggregationKey = op.getConf().getStatsAggPrefix();
List<String> inputPaths = new ArrayList<String>();
switch (parseInfo.getTableSpec().specType) {
case TABLE_ONLY:
inputPaths.add(parseInfo.getTableSpec().tableHandle.getPath().toString());
break;
case STATIC_PARTITION:
Partition part = parseInfo.getTableSpec().partHandle;
try {
aggregationKey += Warehouse.makePartPath(part.getSpec());
} catch (MetaException e) {
throw new SemanticException(ErrorMsg.ANALYZE_TABLE_PARTIALSCAN_AGGKEY.getMsg(
part.getPartitionPath().toString() + e.getMessage()));
}
inputPaths.add(part.getPartitionPath().toString());
break;
default:
assert false;
}
// scan work
PartialScanWork scanWork = new PartialScanWork(inputPaths);
scanWork.setMapperCannotSpanPartns(true);
scanWork.setAggKey(aggregationKey);
// stats work
statsWork.setPartialScanAnalyzeCommand(true);
// partial scan task
DriverContext driverCxt = new DriverContext();
Task<PartialScanWork> psTask = TaskFactory.get(scanWork, parseCtx.getConf());
psTask.initialize(parseCtx.getConf(), null, driverCxt);
psTask.setWork(scanWork);
// task dependency
ctx.getRootTasks().remove(currTask);
ctx.getRootTasks().add(psTask);
psTask.addDependentTask(statsTask);
List<Task<? extends Serializable>> parentTasks = new ArrayList<Task<? extends Serializable>>();
parentTasks.add(psTask);
statsTask.setParentTasks(parentTasks);
}
}