Re: Add 64-bit XIDs into PostgreSQL 15

Robert Haas <robertmhaas@gmail.com>

From: Robert Haas <robertmhaas@gmail.com>

To: Andres Freund <andres@anarazel.de>

Cc: Heikki Linnakangas <hlinnaka@iki.fi>, Maxim Orlov <orlovmg@gmail.com>, Yura Sokolov <y.sokolov@postgrespro.ru>, Evgeny Voropaev <evgeny.voropaev@tantorlabs.com>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>, Andrey Borodin <x4mmm@yandex-team.ru>

Date: 2026-02-09T13:40:48Z

Lists: pgsql-hackers

On Sun, Feb 8, 2026 at 12:21 PM Andres Freund <andres@anarazel.de> wrote:
> On the topic of pd_prune_xid - I've been wondering if, instead of the double
> xmax approach, the high bits of the 64bit xid could be stored in pd_prune_xid,
> signified by a flag on the page indicating so.

We potentially have both XIDs and MXIDs to worry about, though.

-- 
Robert Haas
EDB: http://www.enterprisedb.com

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

Add SLRU tests for 64-bit page case
- a60b8a58f435 17.0 landed
Make use FullTransactionId in 2PC filenames
- 5a1dfde8334b 17.0 landed
Use larger segment file names for pg_notify
- 2cdf131c46e6 17.0 landed
Index SLRUs by 64-bit integers rather than by 32-bit integers
- 4ed8f0913bfd 17.0 landed