Re: Add 64-bit XIDs into PostgreSQL 15

Aleksander Alekseev <aleksander@timescale.com>

From: Aleksander Alekseev <aleksander@timescale.com>
To: pgsql-hackers@lists.postgresql.org
Cc: Maxim Orlov <orlovmg@gmail.com>, Dilip Kumar <dilipbalaut@gmail.com>, Thom Brown <thom@linux.com>, Zhang Mingli <zmlpostgres@gmail.com>, Michael Paquier <michael@paquier.xyz>, Justin Pryzby <pryzby@telsasoft.com>, Pavel Borisov <pashkin.elfe@gmail.com>, Stephen Frost <sfrost@snowman.net>, Alexander Korotkov <aekorotkov@gmail.com>, Andres Freund <andres@anarazel.de>, Ilya Anfimov <ilan@tzirechnoy.com>
Date: 2022-11-14T18:07:52Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →
  1. Add SLRU tests for 64-bit page case

  2. Make use FullTransactionId in 2PC filenames

  3. Use larger segment file names for pg_notify

  4. Index SLRUs by 64-bit integers rather than by 32-bit integers

Hi hackers,

> Thanks, done!

Dilip Kumar asked a good question in the thread about the 0001..0003
subset [1]. I would like to duplicate it here to make sure it was not
missed by mistake:

"""
Have we measured the WAL overhead because of this patch set? maybe
these particular patches will not impact but IIUC this is ground work
for making xid 64 bit. So each XLOG record size will increase at
least by 4 bytes because the XLogRecord contains the xid.
"""

Do we have an estimate on this?

[1]: https://www.postgresql.org/message-id/CAFiTN-uudj2PY8GsUzFtLYFpBoq_rKegW3On_8ZHdxB1mVv3-A%40mail.gmail.com

-- 
Best regards,
Aleksander Alekseev