org.apache.druid.query.groupby.strategy

Interface GroupByStrategy

All Known Implementing Classes:

GroupByStrategyV1, GroupByStrategyV2

public interface GroupByStrategy

Method Summary

Modifier and Type	Method and Description
Sequence<Row>	applyPostProcessing(Sequence<Row> results, GroupByQuery query)
QueryRunner<Row>	createIntervalChunkingRunner(IntervalChunkingQueryRunnerDecorator decorator, QueryRunner<Row> runner, GroupByQueryQueryToolChest toolChest) Decorate a runner with an interval chunking decorator.
boolean	doMergeResults(GroupByQuery query) Indicates if this query should undergo "mergeResults" or not.
boolean	isCacheable(boolean willMergeRunners) Indicates this strategy is cacheable or not.
Sequence<Row>	mergeResults(QueryRunner<Row> baseRunner, GroupByQuery query, Map<String,Object> responseContext)
QueryRunner<Row>	mergeRunners(com.google.common.util.concurrent.ListeningExecutorService exec, Iterable<QueryRunner<Row>> queryRunners)
GroupByQueryResource	prepareResource(GroupByQuery query, boolean willMergeRunners) Initializes resources required for a broker to process the given query.
Sequence<Row>	process(GroupByQuery query, StorageAdapter storageAdapter)
Sequence<Row>	processSubqueryResult(GroupByQuery subquery, GroupByQuery query, GroupByQueryResource resource, Sequence<Row> subqueryResult, boolean wasQueryPushedDown)
Sequence<Row>	processSubtotalsSpec(GroupByQuery query, GroupByQueryResource resource, Sequence<Row> queryResult)
boolean	supportsNestedQueryPushDown()

Method Detail

prepareResource

GroupByQueryResource prepareResource(GroupByQuery query,
                                     boolean willMergeRunners)

Initializes resources required for a broker to process the given query.

Parameters:

query - a groupBy query to be processed

Returns:

broker resource

isCacheable

boolean isCacheable(boolean willMergeRunners)

Indicates this strategy is cacheable or not. The willMergeRunners parameter can be used for distinguishing the caller is a broker or a data node.

Parameters:

willMergeRunners - indicates that QueryRunnerFactory.mergeRunners(ExecutorService, Iterable) will be called on the cached by-segment results

Returns:

true if this strategy is cacheable, otherwise false.

doMergeResults

boolean doMergeResults(GroupByQuery query)

Indicates if this query should undergo "mergeResults" or not.

createIntervalChunkingRunner

QueryRunner<Row> createIntervalChunkingRunner(IntervalChunkingQueryRunnerDecorator decorator,
                                              QueryRunner<Row> runner,
                                              GroupByQueryQueryToolChest toolChest)

Decorate a runner with an interval chunking decorator.

mergeResults

Sequence<Row> mergeResults(QueryRunner<Row> baseRunner,
                           GroupByQuery query,
                           Map<String,Object> responseContext)

applyPostProcessing

Sequence<Row> applyPostProcessing(Sequence<Row> results,
                                  GroupByQuery query)

processSubqueryResult

Sequence<Row> processSubqueryResult(GroupByQuery subquery,
                                    GroupByQuery query,
                                    GroupByQueryResource resource,
                                    Sequence<Row> subqueryResult,
                                    boolean wasQueryPushedDown)

processSubtotalsSpec

Sequence<Row> processSubtotalsSpec(GroupByQuery query,
                                   GroupByQueryResource resource,
                                   Sequence<Row> queryResult)

mergeRunners

QueryRunner<Row> mergeRunners(com.google.common.util.concurrent.ListeningExecutorService exec,
                              Iterable<QueryRunner<Row>> queryRunners)

process

Sequence<Row> process(GroupByQuery query,
                      StorageAdapter storageAdapter)

supportsNestedQueryPushDown

boolean supportsNestedQueryPushDown()