Package org.apache.druid.query.groupby.epinephelinae

Class GroupByQueryEngine

java.lang.Object

org.apache.druid.query.groupby.epinephelinae.GroupByQueryEngine

public class GroupByQueryEngine
extends Object

Contains logic to process a groupBy query on a single CursorFactory in a non-vectorized manner. Processing returns a Sequence of ResultRow objects that are not guaranteed to be in any particular order, and may not even be fully grouped. It is expected that a downstream GroupByMergingQueryRunner will finish grouping these results.

This code runs on anything that processes CursorFactory directly, typically data servers like Historicals.

Used for non-vectorized processing by GroupingEngine.process(org.apache.druid.query.groupby.GroupByQuery, org.apache.druid.segment.CursorFactory, org.apache.druid.segment.TimeBoundaryInspector, org.apache.druid.collections.NonBlockingPool<java.nio.ByteBuffer>, org.apache.druid.query.groupby.GroupByQueryMetrics). This code runs on data servers, like Historicals and Peons, and also Brokers, if they operate on local datasources like inlined data wherein the broker needs to process some portion of data like the data server

See Also:

• for vectorized version of this class

Method Summary

Modifier and Type	Method	Description
static boolean	canPushDownLimit(ColumnSelectorFactory columnSelectorFactory, String columnName)	check if a column will operate correctly with LimitedBufferHashGrouper for query limit pushdown
static Sequence<ResultRow>	process(GroupByQuery query, TimeBoundaryInspector timeBoundaryInspector, CursorHolder cursorHolder, CursorBuildSpec buildSpec, ByteBuffer processingBuffer, org.joda.time.DateTime fudgeTimestamp, GroupByQueryConfig querySpecificConfig, DruidProcessingConfig processingConfig)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details

process

public static Sequence<ResultRow> process(GroupByQuery query,
 @Nullable
 TimeBoundaryInspector timeBoundaryInspector,
 CursorHolder cursorHolder,
 CursorBuildSpec buildSpec,
 ByteBuffer processingBuffer,
 @Nullable
 org.joda.time.DateTime fudgeTimestamp,
 GroupByQueryConfig querySpecificConfig,
 DruidProcessingConfig processingConfig)

canPushDownLimit

public static boolean canPushDownLimit(ColumnSelectorFactory columnSelectorFactory,
 String columnName)

check if a column will operate correctly with LimitedBufferHashGrouper for query limit pushdown