Major Description
After months of development, I feel tez branch reaches to a point we can merge back into trunk. The merge will not introduce any known regression, that is:
1. All existing unit tests pass in mr mode
2. All existing e2e tests pass in mr mode
3. No backward-incompitable changes
The tez branch is stable enough, that is:
1. All migrated unit tests pass in tez mode
2. Vast majority of e2e tests pass in tez mode, minor number of failures are properly investigated
Ongoing tez work can continue after the merge. It is unlikely major changes to other part of Pig code will be involved going forward.
Known limitations for Pig on tez at this moment:
1. Some unit tests are not ported (PIG-3840)
2. Several operators are missing: native, merge-sparse join, collected cogroup
3. auto-parallelism is not in (PIG-3846)