* Add compaction task
* added doc
* use combining aggregators
* address comments
* add support for dimensionsSpec
* fix getUniqueDims and getUniqueMetics
* find unique dimensionsSpec
* fix compilation
* add unit test
* fix test
* fix test
* test for different dimension orderings and types, and doc for type and ordering
* add control for custom ordering and type
* update doc
* fix compile
* fix compile
* add segments param
* fix serde error
* fix build
* Early publishing segments in the middle of data ingestion
* Remove unnecessary logs
* Address comments
* Refactoring the patch according to #4292 and address comments
* Set the total shard number of NumberedShardSpec to 0
* refactoring
* Address comments
* Fix tests
* Address comments
* Fix sync problem of committer and retry push only
* Fix doc
* Fix build failure
* Address comments
* Fix compilation failure
* Fix transient test failure
* Remove ability to create segments in v8 format
* Fix IndexGeneratorJobTest
* Fix parameterized test name in IndexMergerTest
* Remove extra legacy merging stuff
* Remove legacy serializer builders
* Remove ConciseBitmapIndexMergerTest and RoaringBitmapIndexMergerTest
* Refactoring Appenderator
1) Added publishExecutor and handoffExecutor for background publishing and handing segments off
2) Change add() to not move segments out in it
* Address comments
1) Remove publishTimeout for KafkaIndexTask
2) Simplifying registerHandoff()
3) Add increamental handoff test
* Remove unused variable
* Add persist() to Appenderator and more tests for AppenderatorDriver
* Remove unused imports
* Fix strict build
* Address comments
* Add SameIntervalMergeTask for easier usage of MergeTask
* fix a bug and add ut
* remove same_interval_merge_sub from Task.java and remove other no needed code
* ability to not rollup at index time, make pre aggregation an option
* rename getRowIndexForRollup to getPriorIndex
* fix doc misspelling
* test query using no-rollup indexes
* fix benchmark fail due to jmh bug
To bring consistency to docs and source this commit changes the default
values for maxRowsInMemory and rowFlushBoundary to 75000 after
discussion in PR https://github.com/druid-io/druid/pull/2457.
The previous default was 500000 and it's lower now on the grounds that
it's better for a default to be somewhat less efficient, and work,
than to reach for the stars and possibly result in
"OutOfMemoryError: java heap space" errors.