io.druid.query.groupby.strategy

Interface GroupByStrategy

All Known Implementing Classes:

GroupByStrategyV1, GroupByStrategyV2

public interface GroupByStrategy

Method Summary

Modifier and Type	Method and Description
QueryRunner<io.druid.data.input.Row>	createIntervalChunkingRunner(IntervalChunkingQueryRunnerDecorator decorator, QueryRunner<io.druid.data.input.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<io.druid.data.input.Row>	mergeResults(QueryRunner<io.druid.data.input.Row> baseRunner, GroupByQuery query, Map<String,Object> responseContext)
QueryRunner<io.druid.data.input.Row>	mergeRunners(com.google.common.util.concurrent.ListeningExecutorService exec, Iterable<QueryRunner<io.druid.data.input.Row>> queryRunners)
GroupByQueryResource	prepareResource(GroupByQuery query, boolean willMergeRunners) Initializes resources required for a broker to process the given query.
Sequence<io.druid.data.input.Row>	process(GroupByQuery query, StorageAdapter storageAdapter)
Sequence<io.druid.data.input.Row>	processSubqueryResult(GroupByQuery subquery, GroupByQuery query, GroupByQueryResource resource, Sequence<io.druid.data.input.Row> subqueryResult)

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<io.druid.data.input.Row> createIntervalChunkingRunner(IntervalChunkingQueryRunnerDecorator decorator,
                                                                  QueryRunner<io.druid.data.input.Row> runner,
                                                                  GroupByQueryQueryToolChest toolChest)

Decorate a runner with an interval chunking decorator.

mergeResults

Sequence<io.druid.data.input.Row> mergeResults(QueryRunner<io.druid.data.input.Row> baseRunner,
                                               GroupByQuery query,
                                               Map<String,Object> responseContext)

processSubqueryResult

Sequence<io.druid.data.input.Row> processSubqueryResult(GroupByQuery subquery,
                                                        GroupByQuery query,
                                                        GroupByQueryResource resource,
                                                        Sequence<io.druid.data.input.Row> subqueryResult)

mergeRunners

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

process

Sequence<io.druid.data.input.Row> process(GroupByQuery query,
                                          StorageAdapter storageAdapter)