Functional stateless tests (ubsan) — fail: 1, passed: 2440, skipped: 9

2020-11-14 03:24:48 01247_optimize_distributed_group_by_sharding_key:                       [ FAIL ] 0.34 sec. - return code 101
2020-11-14 03:24:48 Received exception from server (version 20.12.1):
2020-11-14 03:24:48 Code: 101. DB::Exception: Received from localhost:9000. DB::Exception: Received from 127.0.0.2:9000. DB::Exception: Unexpected packet Data received from client. 

Not related, but interesting, I will take a look

Cc @4ertus2

The logic is too complicated.
I strongly not recommend to use Merge over Distributed.

Indeed (this use case looks really doubtful)

PS. Do I understand correctly, that it simply defies the purpose of GLOBAL JOIN? So, data won't be sent to remote servers for joining...

Kind of, but temporary table will be still created and sent to the remote, while this should not happen.

Hello guys, I see, that you backported that bug fix into version version 20.9
But we still get missing columns exceptions with versions 20.9.7.11
I ran queries like in test file in that PR and got exceptions.

Hello guys, I see, that you backported that bug fix into version version 20.9 But we still get missing columns exceptions with versions 20.9.7.11 I ran queries like in test file in that PR and got exceptions.

The fix was not backported.
The backport PRs are Closed, not Merged.

@SaltTan Thank you for explanation. Do not you know they want to backport it?