use of org.apache.phoenix.iterate.OrderedAggregatingResultIterator in project phoenix by apache.
the class AggregatePlan method newIterator.
@Override
protected ResultIterator newIterator(ParallelScanGrouper scanGrouper, Scan scan) 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) : new ParallelIterators(this, null, wrapParallelIteratorFactory(), scan, false);
estimatedRows = iterators.getEstimatedRowCount();
estimatedSize = iterators.getEstimatedByteCount();
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;
}
use of org.apache.phoenix.iterate.OrderedAggregatingResultIterator in project phoenix by apache.
the class ClientAggregatePlan method iterator.
@Override
public ResultIterator iterator(ParallelScanGrouper scanGrouper, Scan scan) throws SQLException {
ResultIterator iterator = delegate.iterator(scanGrouper, scan);
if (where != null) {
iterator = new FilterResultIterator(iterator, where);
}
AggregatingResultIterator aggResultIterator;
if (groupBy.isEmpty()) {
aggResultIterator = new ClientUngroupedAggregatingResultIterator(LookAheadResultIterator.wrap(iterator), serverAggregators);
aggResultIterator = new UngroupedAggregatingResultIterator(LookAheadResultIterator.wrap(aggResultIterator), clientAggregators);
} else {
if (!groupBy.isOrderPreserving()) {
int thresholdBytes = context.getConnection().getQueryServices().getProps().getInt(QueryServices.SPOOL_THRESHOLD_BYTES_ATTRIB, QueryServicesOptions.DEFAULT_SPOOL_THRESHOLD_BYTES);
List<Expression> keyExpressions = groupBy.getKeyExpressions();
List<OrderByExpression> keyExpressionOrderBy = Lists.newArrayListWithExpectedSize(keyExpressions.size());
for (Expression keyExpression : keyExpressions) {
keyExpressionOrderBy.add(new OrderByExpression(keyExpression, false, true));
}
iterator = new OrderedResultIterator(iterator, keyExpressionOrderBy, thresholdBytes, null, null, projector.getEstimatedRowByteSize());
}
aggResultIterator = new ClientGroupedAggregatingResultIterator(LookAheadResultIterator.wrap(iterator), serverAggregators, groupBy.getKeyExpressions());
aggResultIterator = new GroupedAggregatingResultIterator(LookAheadResultIterator.wrap(aggResultIterator), clientAggregators);
}
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(resultScanner, 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;
}
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