On 2022-Jan-21, houzj.fnst@fujitsu.com wrote:
> Personally, I'm a little hesitant to put the check at DDL level, because
> adding check at DDLs like ATTACH PARTITION/CREATE PARTITION OF ( [1]
> explained why we need to check these DDLs) looks a bit restrictive and
> user might also complain about that. Put the check in
> CheckCmdReplicaIdentity seems more acceptable because it is consistent
> with the existing behavior which has few complaints from users AFAIK.
I think logical replication is currently so limited that there's very
few people that can put it to real use. So I suggest we should not take
the small number of complaints about the current behavior as very
valuable, because it just means that not a lot of people are using
logical replication in the first place. But once these new
functionalities are introduced, it will start to become actually useful
and it will be then when users will exercise and notice weird behavior.
If ATTACH PARTITION or CREATE TABLE .. PARTITION OF don't let you
specify replica identity, I suspect it's because both partitioning and
logical replication were developed in parallel, and neither gave too
much thought to the other. So these syntax corners went unnoticed.
I suspect that a better way to attack this problem is to let ALTER TABLE
... ATTACH PARTITION and CREATE TABLE .. PARTITION OF specify a replica
identity as necessary.
My suggestion is to avoid painting us into a corner from which it will
be impossible to get out later.
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Álvaro Herrera 39°49'30"S 73°17'W — https://www.EnterpriseDB.com/
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