/**
* 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.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.hive.conf.HiveConf;
import org.apache.hadoop.hive.metastore.api.Index;
import org.apache.hadoop.hive.ql.Driver;
import org.apache.hadoop.hive.ql.exec.TableScanOperator;
import org.apache.hadoop.hive.ql.exec.Task;
import org.apache.hadoop.hive.ql.hooks.ReadEntity;
import org.apache.hadoop.hive.ql.hooks.WriteEntity;
import org.apache.hadoop.hive.ql.index.IndexMetadataChangeTask;
import org.apache.hadoop.hive.ql.index.IndexMetadataChangeWork;
import org.apache.hadoop.hive.ql.metadata.Hive;
import org.apache.hadoop.hive.ql.metadata.HiveException;
import org.apache.hadoop.hive.ql.metadata.Partition;
import org.apache.hadoop.hive.ql.metadata.Table;
import org.apache.hadoop.hive.ql.optimizer.physical.index.IndexWhereProcessor;
import org.apache.hadoop.hive.ql.parse.ParseContext;
import org.apache.hadoop.hive.ql.parse.PrunedPartitionList;
import org.apache.hadoop.hive.ql.parse.SemanticException;
/**
* Utility class for index support.
* Currently used for BITMAP and AGGREGATE index
*
*/
public final class IndexUtils {
private static final Log LOG = LogFactory.getLog(IndexWhereProcessor.class.getName());
private static final Map<Index, Table> indexToIndexTable = new HashMap<Index, Table>();
private IndexUtils(){
}
/**
* Check the partitions used by the table scan to make sure they also exist in the
* index table.
* @param pctx
* @param indexes
* @return partitions used by query. null if they do not exist in index table
* @throws HiveException
*/
public static Set<Partition> checkPartitionsCoveredByIndex(TableScanOperator tableScan,
ParseContext pctx,
Map<Table, List<Index>> indexes)
throws HiveException {
Hive hive = Hive.get(pctx.getConf());
// make sure each partition exists on the index table
PrunedPartitionList queryPartitionList = pctx.getOpToPartList().get(tableScan);
Set<Partition> queryPartitions = queryPartitionList.getPartitions();
if (queryPartitions == null || queryPartitions.isEmpty()) {
return null;
}
for (Partition part : queryPartitions) {
List<Table> sourceIndexTables = getIndexTables(hive, part, indexes);
if (!containsPartition(hive, part, indexes)) {
return null; // problem if it doesn't contain the partition
}
}
return queryPartitions;
}
/**
* return index tables associated with a given base table
*/
private List<Table> getIndexTables(Hive hive, Table table,
Map<Table, List<Index>> indexes) throws
HiveException {
List<Table> indexTables = new ArrayList<Table>();
if (indexes == null || indexes.get(table) == null) {
return indexTables;
}
for (Index index : indexes.get(table)) {
Table indexTable = hive.getTable(index.getIndexTableName());
indexToIndexTable.put(index, indexTable);
indexTables.add(indexTable);
}
return indexTables;
}
/**
* return index tables associated with the base table of the partition
*/
private static List<Table> getIndexTables(Hive hive, Partition part,
Map<Table, List<Index>> indexes) throws HiveException {
List<Table> indexTables = new ArrayList<Table>();
Table partitionedTable = part.getTable();
if (indexes == null || indexes.get(partitionedTable) == null) {
return indexTables;
}
for (Index index : indexes.get(partitionedTable)) {
Table indexTable = hive.getTable(index.getIndexTableName());
indexToIndexTable.put(index, indexTable);
indexTables.add(indexTable);
}
return indexTables;
}
/**
* check that every index table contains the given partition and is fresh
*/
private static boolean containsPartition(Hive hive, Partition part,
Map<Table, List<Index>> indexes)
throws HiveException {
HashMap<String, String> partSpec = part.getSpec();
if (indexes == null || indexes.get(part.getTable()) == null) {
return false;
}
if (partSpec.isEmpty()) {
// empty specs come from non-partitioned tables
return isIndexTableFresh(hive, indexes.get(part.getTable()), part.getTable());
}
for (Index index : indexes.get(part.getTable())) {
Table indexTable = indexToIndexTable.get(index);
// get partitions that match the spec
List<Partition> matchingPartitions = hive.getPartitions(indexTable, partSpec);
if (matchingPartitions == null || matchingPartitions.size() == 0) {
LOG.info("Index table " + indexTable + "did not contain built partition that matched " + partSpec);
return false;
} else if (!isIndexPartitionFresh(hive, index, part)) {
return false;
}
}
return true;
}
/**
* Check the index partitions on a parttioned table exist and are fresh
*/
private static boolean isIndexPartitionFresh(Hive hive, Index index,
Partition part) throws HiveException {
LOG.info("checking index staleness...");
try {
FileSystem partFs = part.getPartitionPath().getFileSystem(hive.getConf());
FileStatus partFss = partFs.getFileStatus(part.getPartitionPath());
String ts = index.getParameters().get(part.getSpec().toString());
if (ts == null) {
return false;
}
long indexTs = Long.parseLong(ts);
LOG.info(partFss.getModificationTime());
LOG.info(ts);
if (partFss.getModificationTime() > indexTs) {
LOG.info("index is stale on the partitions that matched " + part.getSpec());
return false;
}
} catch (IOException e) {
LOG.info("failed to grab timestamp info");
throw new HiveException(e);
}
return true;
}
/**
* Check that the indexes on the unpartioned table exist and are fresh
*/
private static boolean isIndexTableFresh(Hive hive, List<Index> indexes, Table src)
throws HiveException {
//check that they exist
if (indexes == null || indexes.size() == 0) {
return false;
}
//check that they are not stale
for (Index index : indexes) {
LOG.info("checking index staleness...");
try {
FileSystem srcFs = src.getPath().getFileSystem(hive.getConf());
FileStatus srcFss= srcFs.getFileStatus(src.getPath());
String ts = index.getParameters().get("base_timestamp");
if (ts == null) {
return false;
}
long indexTs = Long.parseLong(ts);
LOG.info(srcFss.getModificationTime());
LOG.info(ts);
if (srcFss.getModificationTime() > indexTs) {
LOG.info("index is stale ");
return false;
}
} catch (IOException e) {
LOG.info("failed to grab timestamp info");
throw new HiveException(e);
}
}
return true;
}
/**
* Get a list of indexes on a table that match given types.
*/
public static List<Index> getIndexes(Table baseTableMetaData, List<String> matchIndexTypes)
throws SemanticException {
List<Index> matchingIndexes = new ArrayList<Index>();
List<Index> indexesOnTable = null;
try {
indexesOnTable = baseTableMetaData.getAllIndexes((short) -1); // get all indexes
} catch (HiveException e) {
throw new SemanticException("Error accessing metastore", e);
}
for (Index index : indexesOnTable) {
String indexType = index.getIndexHandlerClass();
if (matchIndexTypes.contains(indexType)) {
matchingIndexes.add(index);
}
}
return matchingIndexes;
}
public static Task<?> createRootTask(HiveConf builderConf, Set<ReadEntity> inputs,
Set<WriteEntity> outputs, StringBuilder command,
LinkedHashMap<String, String> partSpec,
String indexTableName, String dbName){
// Don't try to index optimize the query to build the index
HiveConf.setBoolVar(builderConf, HiveConf.ConfVars.HIVEOPTINDEXFILTER, false);
Driver driver = new Driver(builderConf);
driver.compile(command.toString());
Task<?> rootTask = driver.getPlan().getRootTasks().get(0);
inputs.addAll(driver.getPlan().getInputs());
outputs.addAll(driver.getPlan().getOutputs());
IndexMetadataChangeWork indexMetaChange = new IndexMetadataChangeWork(partSpec,
indexTableName, dbName);
IndexMetadataChangeTask indexMetaChangeTsk = new IndexMetadataChangeTask();
indexMetaChangeTsk.setWork(indexMetaChange);
rootTask.addDependentTask(indexMetaChangeTsk);
return rootTask;
}
}