It will be useful to add such a command so that users don't see an error when adding an existing partition.
ALTER TABLE ADD IF NOT EXISTS PARTITION is not atomic
Do we need this for branch-0.5?
Usually we don't add new features to an existing branch. Only bug fixes should go into branches.
But given that nothing has been released from branch-0.5 yet, I think we can add this since it's low risk.
+1. Will test and commit.
Committed. Thanks Paul!