Horton

Re: Possible bug in logical replication.

Arseny Sher <a.sher@postgrespro.ru>

View thread View on postgr.es
From: Arseny Sher <a.sher@postgrespro.ru>
To: Michael Paquier <michael@paquier.xyz>
Cc: Kyotaro HORIGUCHI <horiguchi.kyotaro@lab.ntt.co.jp>, sawada.mshk@gmail.com, a.sher@postgrespro.ru, k.knizhnik@postgrespro.ru, pgsql-hackers@lists.postgresql.org
Date: 2018-05-25T06:57:18Z
Lists: pgsql-hackers 
Michael Paquier <michael@paquier.xyz> writes:

> Maybe I am being too naive, but wouldn't it be just enough to update the
> confirmed flush LSN to ctx->reader->ReadRecPtr?  This way, the slot
> advances up to the beginning of the last record where user wants to
> advance, and not the beginning of the next record:

Same problem should be handled at pg_logical_slot_get_changes_guts and
apply worker feedback; and there is a convention that all commits since
confirmed_flush must be decoded, so we risk decoding such boundary
commit twice.

--
Arseny Sher
Postgres Professional: http://www.postgrespro.com
The Russian Postgres Company

Commits

  1. Rewrite comments in replication slot advance implementation

  2. Fix a couple of bugs with replication slot advancing feature

  3. Ability to advance replication slots