* Working
* add test
* doc
* fix test
* split other integration test
* exclude other-index from other tests
* doc anchor fix
* adjust task slots and number of merge tasks
* spell check
* reduce maxNumConcurrentSubTasks to 1
* maxNumConcurrentSubtasks for range partitinoing
* reduce memory for historical
* change group name
* Fix handling of 'join' on top of 'union' datasources.
The problem is that unions are typically rewritten into a series of
individual queries on the underlying tables, but this isn't done when
the union is wrapped in a join.
The main changes are in UnionQueryRunner:
1) Replace an instanceof UnionQueryRunner check with DataSourceAnalysis.
2) Replace a "query.withDataSource" call with a new function, "Queries.withBaseDataSource".
Together, these enable UnionQueryRunner to "see through" a join.
* Tests.
* Adjust heap sizes for integration tests.
* Different approach, more tests.
* Tweak.
* Styling.