Horton

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

Ashutosh Sharma <ashu.coek88@gmail.com>

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From: Ashutosh Sharma <ashu.coek88@gmail.com>
To: "Andrey M. Borodin" <x4mmm@yandex-team.ru>, MBeena Emerson <mbeena.emerson@gmail.com>
Cc: 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>, Robert Haas <robertmhaas@gmail.com>
Date: 2020-07-31T12:52:23Z
Lists: pgsql-hackers

Attachments

Attached is the new version of patch that addresses the comments from
Andrey and Beena.

On Wed, Jul 29, 2020 at 10:07 AM Ashutosh Sharma <ashu.coek88@gmail.com>
wrote:

> Hi Beena,
>
> Thanks for the review.
>
> 1. We would be marking buffer dirty and writing wal even if we have
>> not done any changes( ex if we pass invalid/dead tids). Maybe we can
>> handle this better?
>>
>
> Yeah, we can skip this when nothing has changed. Will take care of it in
> the next version of patch.
>
>
>> cosmetic changes
>> 1. Maybe "HTupleSurgicalOption" instead of "HTupleForceOption" and
>> also the variable names could use surgery instead.
>>
>
> I think that looks fine. I would rather prefer the word "Force" just
> because all the enum options contain the word "Force" in it.
>
>
>> 2. extension comment pg_surgery.control "extension to perform surgery
>> the damaged heap table" -> "extension to perform surgery on the
>> damaged heap table"
>>
>
> Okay, will fix that typo.
>
> --
> With Regards,
> Ashutosh Sharma
> EnterpriseDB:http://www.enterprisedb.com
>

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.