New classes:
- ParallelPlanner: creates build plans, assigns plans to cohorts
- JoinBuildSink: DataSink for plan fragments that materialize build sides
- ids for plans, hash tables, plan fragments
Tests: this adds a new test file section PARALLELPLANS and augments the tpc-h/-ds tests with
those sections.
In the interest of keeping this patch small I didn't augment other test files with that
section yet (which will happen at a later date, to cover more corner cases).
Change-Id: Ic3c34dd3f9190a131e6f03d901b4bfcd164a5174
Reviewed-on: http://gerrit.cloudera.org:8080/2846
Tested-by: Internal Jenkins
Reviewed-by: Marcel Kornacker <marcel@cloudera.com>