Horton

Re: recovering from "found xmin ... from before relfrozenxid ..."

Robert Haas <robertmhaas@gmail.com>

View thread View on postgr.es
From: Robert Haas <robertmhaas@gmail.com>
To: Ashutosh Sharma <ashu.coek88@gmail.com>
Cc: Masahiko Sawada <masahiko.sawada@2ndquadrant.com>, "Andrey M. Borodin" <x4mmm@yandex-team.ru>, MBeena Emerson <mbeena.emerson@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>, Andres Freund <andres@anarazel.de>, Peter Eisentraut <peter.eisentraut@2ndquadrant.com>, Tom Lane <tgl@sss.pgh.pa.us>, Stephen Frost <sfrost@snowman.net>
Date: 2020-08-11T14:03:29Z
Lists: pgsql-hackers 
On Tue, Aug 11, 2020 at 3:39 AM Ashutosh Sharma <ashu.coek88@gmail.com> wrote:
> The other two messages for reporting unused items and dead items
> remain the same. Hence, with above change, we would be reporting the
> following 4 messages:
>
> NOTICE:  skipping all the tids in block %u for relation "%s" because
> the block number is out of range
>
> NOTICE:  skipping tid (%u, %u) for relation "%s" because the item
> number is out of range for this block
>
> NOTICE:  skipping tid (%u, %u) for relation "%s" because it is marked dead
>
> NOTICE:  skipping tid (%u, %u) for relation "%s" because it is marked unused
>
> Please let me know if you are okay with the above changes or not?

That seems broadly reasonable, but I would suggest phrasing the first
message like this:

skipping block %u for relation "%s" because the block number is out of range

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company

Commits

  1. Fix wrong data table horizon computation during backend startup.

  2. Centralize horizon determination for temp tables, fixing bug due to skew.

  3. pg_surgery: Try to stabilize regression tests.

  4. New contrib module, pg_surgery, with heap surgery functions.

  5. Set cutoff xmin more aggressively when vacuuming a temporary table.

  6. snapshot scalability: Don't compute global horizons while building snapshots.

  7. Introduce vacuum errcontext to display additional information.