Re: WIP: WAL prefetch (another approach)

Simon Riggs <simon.riggs@enterprisedb.com>

From: Simon Riggs <simon.riggs@enterprisedb.com>
To: Thomas Munro <thomas.munro@gmail.com>
Cc: Julien Rouhaud <rjuju123@gmail.com>, Ashutosh Sharma <ashu.coek88@gmail.com>, Daniel Gustafsson <daniel@yesql.se>, Stephen Frost <sfrost@snowman.net>, Alvaro Herrera <alvherre@2ndquadrant.com>, Andres Freund <andres@anarazel.de>, David Steele <david@pgmasters.net>, Dmitry Dolgov <9erthalion6@gmail.com>, Jakub Wartak <Jakub.Wartak@tomtom.com>, Tom Lane <tgl@sss.pgh.pa.us>, Tomas Vondra <tomas.vondra@2ndquadrant.com>, Tomas Vondra <tomas.vondra@enterprisedb.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2022-04-12T13:58:17Z
Lists: pgsql-hackers
On Thu, 7 Apr 2022 at 08:46, Thomas Munro <thomas.munro@gmail.com> wrote:

> With that... I've finally pushed the 0002 patch and will be watching
> the build farm.

This is a nice feature if it is safe to turn off full_page_writes.

When is it safe to do that? On which platform?

I am not aware of any released software that allows full_page_writes
to be safely disabled. Perhaps something has been released recently
that allows this? I think we have substantial documentation about
safety of other settings, so we should carefully document things here
also.

-- 
Simon Riggs                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 →
  1. Fix recovery_prefetch docs.

  2. Prefetch data referenced by the WAL, take II.

  3. Add circular WAL decoding buffer, take II.

  4. Fix generation of ./INSTALL for the distribution tarball

  5. Revert recovery prefetching feature.

  6. Sync guc.c and postgresql.conf.sample with the SGML docs.

  7. Add information of total data processed to replication slot stats.

  8. Doc: Review for "Optionally prefetch referenced data in recovery."

  9. Add circular WAL decoding buffer.

  10. Optionally prefetch referenced data in recovery.

  11. Remove read_page callback from XLogReader.

  12. Provide ReadRecentBuffer() to re-pin buffers by ID.

  13. Provide recovery_init_sync_method=syncfs.

  14. Mark factorial operator, and postfix operators in general, as deprecated.

  15. Rationalize GetWalRcv{Write,Flush}RecPtr().

  16. Support PrefetchBuffer() in recovery.

  17. Prevent hard failures of standbys caused by recycled WAL segments