Horton

Re: XID formatting and SLRU refactorings (was: Add 64-bit XIDs into PostgreSQL 15)

Michael Paquier <michael@paquier.xyz>

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From: Michael Paquier <michael@paquier.xyz>
To: Aleksander Alekseev <aleksander@timescale.com>
Cc: Postgres hackers <pgsql-hackers@lists.postgresql.org>, Alexander Korotkov <aekorotkov@gmail.com>, Noah Misch <noah@leadboat.com>, Maxim Orlov <orlovmg@gmail.com>, Heikki Linnakangas <hlinnaka@iki.fi>, Japin Li <japinli@hotmail.com>, Andres Freund <andres@anarazel.de>, Pavel Borisov <pashkin.elfe@gmail.com>, Peter Eisentraut <peter.eisentraut@enterprisedb.com>
Date: 2024-07-12T01:13:42Z
Lists: pgsql-hackers 
On Thu, Jul 11, 2024 at 01:11:05PM +0300, Aleksander Alekseev wrote:
> Thanks, Michael. I prepared a corrected patchset.

A comment about v3-0001.

-	 * If true, use long segment filenames formed from lower 48 bits of the
-	 * segment number, e.g. pg_xact/000000001234. Otherwise, use short
-	 * filenames formed from lower 16 bits of the segment number e.g.
-	 * pg_xact/1234.
+	 * If true, use long segment filenames. Use short filenames otherwise.
+	 * See SlruFileName().

We're losing some details here even if SlruFileName() has some
explanations, because one would need to read through the snprintf's
04X to know that short file names include 4 characters.  I'm OK to
mention SlruFileName() rather than duplicate the knowledge here, but
SlruFileName() should also be updated to mention the same level of
details with some examples of file names.
--
Michael

Commits

  1. Fix more holes with SLRU code in need of int64 for segment numbers

  2. Use more consistently int64 for page numbers in SLRU-related code

  3. Improve comments in slru.{c,h} about segment name format

  4. Reorder actions in ProcArrayApplyRecoveryInfo()

  5. Fix typo in 5a1dfde8334b

  6. Fix warning due non-standard inline declaration in 4ed8f0913bfdb5f355

  7. Add SLRU tests for 64-bit page case

  8. Make use FullTransactionId in 2PC filenames

  9. Use larger segment file names for pg_notify

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

  11. Keep track of transaction commit timestamps

  12. Handle 5-char filenames in SlruScanDirectory