druid/sql
Gian Merlino d886463253
Add join-related DataSource types, and analysis functionality. (#9235)
* Add join-related DataSource types, and analysis functionality.

Builds on #9111 and implements the datasource analysis mentioned in #8728. Still can't
handle join datasources, but we're a step closer.

Join-related DataSource types:

1) Add "join", "lookup", and "inline" datasources.
2) Add "getChildren" and "withChildren" methods to DataSource, which will be used
   in the future for query rewriting (e.g. inlining of subqueries).

DataSource analysis functionality:

1) Add DataSourceAnalysis class, which breaks down datasources into three components:
   outer queries, a base datasource (left-most of the highest level left-leaning join
   tree), and other joined-in leaf datasources (the right-hand branches of the
   left-leaning join tree).
2) Add "isConcrete", "isGlobal", and "isCacheable" methods to DataSource in order to
   support analysis.

Other notes:

1) Renamed DataSource#getNames to DataSource#getTableNames, which I think is clearer.
   Also, made it a Set, so implementations don't need to worry about duplicates.
2) The addition of "isCacheable" should work around #8713, since UnionDataSource now
   returns false for cacheability.

* Remove javadoc comment.

* Updates reflecting code review.

* Add comments.

* Add more comments.
2020-01-22 14:54:47 -08:00
..
src Add join-related DataSource types, and analysis functionality. (#9235) 2020-01-22 14:54:47 -08:00
pom.xml Set version to 0.18.0-SNAPSHOT (#9109) 2020-01-02 17:55:10 -05:00