Horton

Re: Add 64-bit XIDs into PostgreSQL 15

Aleksander Alekseev <aleksander@timescale.com>

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From: Aleksander Alekseev <aleksander@timescale.com>
To: pgsql-hackers@lists.postgresql.org
Cc: Pavel Borisov <pashkin.elfe@gmail.com>, Chris Travers <chris@orioledata.com>, Chris Travers <chris.travers@gmail.com>, Fedor Sigaev <teodor@sigaev.ru>, Alexander Korotkov <aekorotkov@gmail.com>, Konstantin Knizhnik <knizhnik@garret.ru>, Nikita Glukhov <n.gluhov@postgrespro.ru>, Yura Sokolov <y.sokolov@postgrespro.ru>, Maxim Orlov <orlovmg@gmail.com>
Date: 2022-11-22T14:14:23Z
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,

[ Excluding my personal e-mail from cc:, not sure how it got there.
Please don't cc: to afiskon@gmail.com, I'm not using it for reading
pgsql-hackers@. ]

> I agree with Alexander, that notifications for DBA are a little bit
> outside the scope of the activity in this thread unless we've just
> dropped some existing notifications, considering they're not
> significant anymore. If that was the point, please Chris mention what
> existing notifications you want to return. I don't think it's a big
> deal to have the patch with certain notifications inherited from
> Master branch.

To clarify a bit: currently we DO notify the user about the upcoming
wraparound point [1]:

"""
If for some reason autovacuum fails to clear old XIDs from a table,
the system will begin to emit warning messages like this when the
database's oldest XIDs reach forty million transactions from the
wraparound point:

WARNING:  database "mydb" must be vacuumed within 39985967 transactions
HINT:  To avoid a database shutdown, execute a database-wide VACUUM in
that database.
"""

So I'm not sure how the notification Chris proposes should differ or
why it is in scope of this patch. If the point was to make sure
certain existing notifications will be preserved - sure, why not.

[1]: https://www.postgresql.org/docs/current/routine-vacuuming.html#VACUUM-FOR-WRAPAROUND

-- 
Best regards,
Aleksander Alekseev