org.apache.phoenix.execute.AggregatePlan Maven / Gradle / Ivy
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* distributed with this work for additional information
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* 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.phoenix.execute;
import java.sql.SQLException;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import org.apache.hadoop.hbase.client.Scan;
import org.apache.phoenix.cache.ServerCacheClient.ServerCache;
import org.apache.phoenix.compile.GroupByCompiler.GroupBy;
import org.apache.phoenix.compile.OrderByCompiler.OrderBy;
import org.apache.phoenix.compile.QueryPlan;
import org.apache.phoenix.compile.RowProjector;
import org.apache.phoenix.compile.StatementContext;
import org.apache.phoenix.coprocessor.BaseScannerRegionObserver;
import org.apache.phoenix.coprocessor.GroupedAggregateRegionObserver;
import org.apache.phoenix.coprocessor.UngroupedAggregateRegionObserver;
import org.apache.phoenix.expression.Expression;
import org.apache.phoenix.expression.OrderByExpression;
import org.apache.phoenix.expression.RowKeyExpression;
import org.apache.phoenix.expression.aggregator.Aggregators;
import org.apache.phoenix.hbase.index.util.ImmutableBytesPtr;
import org.apache.phoenix.iterate.AggregatingResultIterator;
import org.apache.phoenix.iterate.BaseResultIterators;
import org.apache.phoenix.iterate.ConcatResultIterator;
import org.apache.phoenix.iterate.DistinctAggregatingResultIterator;
import org.apache.phoenix.iterate.FilterAggregatingResultIterator;
import org.apache.phoenix.iterate.GroupedAggregatingResultIterator;
import org.apache.phoenix.iterate.LimitingResultIterator;
import org.apache.phoenix.iterate.MergeSortRowKeyResultIterator;
import org.apache.phoenix.iterate.OffsetResultIterator;
import org.apache.phoenix.iterate.OrderedAggregatingResultIterator;
import org.apache.phoenix.iterate.OrderedResultIterator;
import org.apache.phoenix.iterate.ParallelIteratorFactory;
import org.apache.phoenix.iterate.ParallelIterators;
import org.apache.phoenix.iterate.ParallelScanGrouper;
import org.apache.phoenix.iterate.PeekingResultIterator;
import org.apache.phoenix.iterate.ResultIterator;
import org.apache.phoenix.iterate.RowKeyOrderedAggregateResultIterator;
import org.apache.phoenix.iterate.SequenceResultIterator;
import org.apache.phoenix.iterate.SerialIterators;
import org.apache.phoenix.iterate.SpoolingResultIterator;
import org.apache.phoenix.iterate.UngroupedAggregatingResultIterator;
import org.apache.phoenix.parse.FilterableStatement;
import org.apache.phoenix.parse.HintNode;
import org.apache.phoenix.query.KeyRange;
import org.apache.phoenix.query.QueryServices;
import org.apache.phoenix.query.QueryServicesOptions;
import org.apache.phoenix.schema.PTable.IndexType;
import org.apache.phoenix.schema.TableRef;
import org.apache.phoenix.schema.types.PInteger;
import org.apache.phoenix.util.ScanUtil;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
*
* Query plan for aggregating queries
*
*
* @since 0.1
*/
public class AggregatePlan extends BaseQueryPlan {
private final Aggregators aggregators;
private final Expression having;
private List splits;
private List> scans;
private static final Logger logger = LoggerFactory.getLogger(AggregatePlan.class);
private boolean isSerial;
public AggregatePlan(StatementContext context, FilterableStatement statement, TableRef table,
RowProjector projector, Integer limit, Integer offset, OrderBy orderBy,
ParallelIteratorFactory parallelIteratorFactory, GroupBy groupBy, Expression having) throws SQLException {
this(context, statement, table, projector, limit, offset, orderBy, parallelIteratorFactory, groupBy, having,
null);
}
private AggregatePlan(StatementContext context, FilterableStatement statement, TableRef table,
RowProjector projector, Integer limit, Integer offset, OrderBy orderBy,
ParallelIteratorFactory parallelIteratorFactory, GroupBy groupBy, Expression having,
Expression dynamicFilter) throws SQLException {
super(context, statement, table, projector, context.getBindManager().getParameterMetaData(), limit, offset,
orderBy, groupBy, parallelIteratorFactory, dynamicFilter);
this.having = having;
this.aggregators = context.getAggregationManager().getAggregators();
boolean hasSerialHint = statement.getHint().hasHint(HintNode.Hint.SERIAL);
boolean canBeExecutedSerially = ScanUtil.canQueryBeExecutedSerially(table.getTable(), orderBy, context);
if (hasSerialHint && !canBeExecutedSerially) {
logger.warn("This query cannot be executed serially. Ignoring the hint");
}
this.isSerial = hasSerialHint && canBeExecutedSerially;
}
public Expression getHaving() {
return having;
}
@Override
public List getSplits() {
if (splits == null)
return Collections.emptyList();
else
return splits;
}
@Override
public List> getScans() {
if (scans == null)
return Collections.emptyList();
else
return scans;
}
private static class OrderingResultIteratorFactory implements ParallelIteratorFactory {
private final QueryServices services;
private final OrderBy orderBy;
public OrderingResultIteratorFactory(QueryServices services,OrderBy orderBy) {
this.services = services;
this.orderBy=orderBy;
}
@Override
public PeekingResultIterator newIterator(StatementContext context, ResultIterator scanner, Scan scan, String tableName, QueryPlan plan) throws SQLException {
Expression expression = RowKeyExpression.INSTANCE;
boolean isNullsLast=false;
boolean isAscending=true;
if(this.orderBy==OrderBy.REV_ROW_KEY_ORDER_BY) {
isNullsLast=true; //which is needed for the whole rowKey.
isAscending=false;
}
OrderByExpression orderByExpression = new OrderByExpression(expression, isNullsLast, isAscending);
int threshold = services.getProps().getInt(QueryServices.SPOOL_THRESHOLD_BYTES_ATTRIB, QueryServicesOptions.DEFAULT_SPOOL_THRESHOLD_BYTES);
return new OrderedResultIterator(scanner, Collections.singletonList(orderByExpression), threshold);
}
}
private static class WrappingResultIteratorFactory implements ParallelIteratorFactory {
private final ParallelIteratorFactory innerFactory;
private final ParallelIteratorFactory outerFactory;
public WrappingResultIteratorFactory(ParallelIteratorFactory innerFactory, ParallelIteratorFactory outerFactory) {
this.innerFactory = innerFactory;
this.outerFactory = outerFactory;
}
@Override
public PeekingResultIterator newIterator(StatementContext context, ResultIterator scanner, Scan scan, String tableName, QueryPlan plan) throws SQLException {
PeekingResultIterator iterator = innerFactory.newIterator(context, scanner, scan, tableName, plan);
return outerFactory.newIterator(context, iterator, scan, tableName, plan);
}
}
private ParallelIteratorFactory wrapParallelIteratorFactory () {
ParallelIteratorFactory innerFactory;
QueryServices services = context.getConnection().getQueryServices();
if (groupBy.isEmpty() || groupBy.isOrderPreserving()) {
if (ScanUtil.isPacingScannersPossible(context)) {
innerFactory = ParallelIteratorFactory.NOOP_FACTORY;
} else {
innerFactory = new SpoolingResultIterator.SpoolingResultIteratorFactory(services);
}
} else {
innerFactory = new OrderingResultIteratorFactory(services,this.getOrderBy());
}
if (parallelIteratorFactory == null) {
return innerFactory;
}
// wrap any existing parallelIteratorFactory
return new WrappingResultIteratorFactory(innerFactory, parallelIteratorFactory);
}
@Override
protected ResultIterator newIterator(ParallelScanGrouper scanGrouper, Scan scan, Map caches) throws SQLException {
if (groupBy.isEmpty()) {
UngroupedAggregateRegionObserver.serializeIntoScan(scan);
} else {
// Set attribute with serialized expressions for coprocessor
GroupedAggregateRegionObserver.serializeIntoScan(scan, groupBy.getScanAttribName(), groupBy.getKeyExpressions());
if (limit != null && orderBy.getOrderByExpressions().isEmpty() && having == null
&& ( ( statement.isDistinct() && ! statement.isAggregate() )
|| ( ! statement.isDistinct() && ( context.getAggregationManager().isEmpty()
|| BaseScannerRegionObserver.KEY_ORDERED_GROUP_BY_EXPRESSIONS.equals(groupBy.getScanAttribName()) ) ) ) ) {
/*
* Optimization to early exit from the scan for a GROUP BY or DISTINCT with a LIMIT.
* We may exit early according to the LIMIT specified if the query has:
* 1) No ORDER BY clause (or the ORDER BY was optimized out). We cannot exit
* early if there's an ORDER BY because the first group may be found last
* in the scan.
* 2) No HAVING clause, since we execute the HAVING on the client side. The LIMIT
* needs to be evaluated *after* the HAVING.
* 3) DISTINCT clause with no GROUP BY. We cannot exit early if there's a
* GROUP BY, as the GROUP BY is processed on the client-side post aggregation
* if a DISTNCT has a GROUP BY. Otherwise, since there are no aggregate
* functions in a DISTINCT, we can exit early regardless of if the
* groups are in row key order or unordered.
* 4) GROUP BY clause with no aggregate functions. This is in the same category
* as (3). If we're using aggregate functions, we need to look at all the
* rows, as otherwise we'd exit early with incorrect aggregate function
* calculations.
* 5) GROUP BY clause along the pk axis, as the rows are processed in row key
* order, so we can early exit, even when aggregate functions are used, as
* the rows in the group are contiguous.
*/
scan.setAttribute(BaseScannerRegionObserver.GROUP_BY_LIMIT,
PInteger.INSTANCE.toBytes(limit + (offset == null ? 0 : offset)));
}
}
BaseResultIterators iterators = isSerial
? new SerialIterators(this, null, null, wrapParallelIteratorFactory(), scanGrouper, scan, caches)
: new ParallelIterators(this, null, wrapParallelIteratorFactory(), scan, false, caches);
estimatedRows = iterators.getEstimatedRowCount();
estimatedSize = iterators.getEstimatedByteCount();
estimateInfoTimestamp = iterators.getEstimateInfoTimestamp();
splits = iterators.getSplits();
scans = iterators.getScans();
AggregatingResultIterator aggResultIterator;
// No need to merge sort for ungrouped aggregation
if (groupBy.isEmpty() || groupBy.isUngroupedAggregate()) {
aggResultIterator = new UngroupedAggregatingResultIterator(new ConcatResultIterator(iterators), aggregators);
// If salted or local index we still need a merge sort as we'll potentially have multiple group by keys that aren't contiguous.
} else if (groupBy.isOrderPreserving() && !(this.getTableRef().getTable().getBucketNum() != null || this.getTableRef().getTable().getIndexType() == IndexType.LOCAL)) {
aggResultIterator = new RowKeyOrderedAggregateResultIterator(iterators, aggregators);
} else {
aggResultIterator = new GroupedAggregatingResultIterator(
new MergeSortRowKeyResultIterator(iterators, 0, this.getOrderBy() == OrderBy.REV_ROW_KEY_ORDER_BY),aggregators);
}
if (having != null) {
aggResultIterator = new FilterAggregatingResultIterator(aggResultIterator, having);
}
if (statement.isDistinct() && statement.isAggregate()) { // Dedup on client if select distinct and aggregation
aggResultIterator = new DistinctAggregatingResultIterator(aggResultIterator, getProjector());
}
ResultIterator resultScanner = aggResultIterator;
if (orderBy.getOrderByExpressions().isEmpty()) {
if (offset != null) {
resultScanner = new OffsetResultIterator(aggResultIterator, offset);
}
if (limit != null) {
resultScanner = new LimitingResultIterator(resultScanner, limit);
}
} else {
int thresholdBytes = context.getConnection().getQueryServices().getProps().getInt(
QueryServices.SPOOL_THRESHOLD_BYTES_ATTRIB, QueryServicesOptions.DEFAULT_SPOOL_THRESHOLD_BYTES);
resultScanner = new OrderedAggregatingResultIterator(aggResultIterator, orderBy.getOrderByExpressions(),
thresholdBytes, limit, offset);
}
if (context.getSequenceManager().getSequenceCount() > 0) {
resultScanner = new SequenceResultIterator(resultScanner, context.getSequenceManager());
}
return resultScanner;
}
@Override
public boolean useRoundRobinIterator() throws SQLException {
return false;
}
}
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