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: Pavel Borisov <pashkin.elfe@gmail.com>
Cc: Andres Freund <andres@anarazel.de>, Ilya Anfimov <ilan@tzirechnoy.com>, Postgres hackers <pgsql-hackers@lists.postgresql.org>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2022-03-02T13:25:33Z
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,

> In this part, I suppose you've found a definite bug. Thanks! There are a couple
> of ways how it could be fixed:
>
> 1. If we enforce checkpoint at replica promotion then we force full-page writes after each page modification afterward.
>
> 2. Maybe it's worth using BufferDesc bit to mark the page as converted to 64xid but not yet written to disk? For example, one of four bits from BUF_USAGECOUNT.
> BM_MAX_USAGE_COUNT  = 5 so it will be enough 3 bits to store it. This will change in-memory page representation but will not need WAL-logging which is impossible on a replica.
>
> What do you think about it?

I'm having difficulties merging and/or testing
v8-0002-Add-64bit-xid.patch since I'm not 100% sure which commit this
patch was targeting. Could you please submit a rebased patch and/or
share your development branch on GitHub?

I agree with Bruce it would be great to deliver this in PG15. Please
let me know if you believe it's unrealistic for any reason so I will
focus on testing and reviewing other patches.

For now, I'm changing the status of the patch to "Waiting on Author".

-- 
Best regards,
Aleksander Alekseev