Re: cutting down the TODO list thread

On Wed, Dec 8, 2021 at 1:40 PM John Naylor <john.naylor@enterprisedb.com> wrote:
>
> It's been a while, but here are a few more suggested
> removals/edits/additions to the TODO list. Any objections or new
> information, let me know:
>
> - Auto-fill the free space map by scanning the buffer cache or by
> checking pages written by the background writer
> http://archives.postgresql.org/pgsql-hackers/2006-02/msg01125.php
> https://www.postgresql.org/message-id/200603011716.16984.peter_e@gmx.net
>
> Both these threads are from 2006, so have nothing to do with the current FSM.

Moved to the Not Worth Doing list.

> - Allow concurrent inserts to use recently created pages rather than
> creating new ones
> http://archives.postgresql.org/pgsql-hackers/2010-05/msg00853.php
>
> Skimming the first few messages, I believe this has been covered by
> commit 719c84c1b? (Extend relations multiple blocks at a time to
> improve scalability.)

Removed.

> - Allow VACUUM FULL and CLUSTER to update the visibility map
>
> This topic has a current CF entry which seems to have stalled, so that
> newer thread would be better to list here than the one from 2013.

Added.

> - Bias FSM towards returning free space near the beginning of the heap
> file, in hopes that empty pages at the end can be truncated by VACUUM
> http://archives.postgresql.org/pgsql-hackers/2009-09/msg01124.php
> https://www.postgresql.org/message-id/20150424190403.GP4369@alvh.no-ip.org
>
> I'm not sure what to think of this, but independently of that, the
> second thread is actually talking about bringing back something like
> the pre-9.0 vacuum full, so maybe it should be its own entry?

Done.

> - Consider a more compact data representation for dead tuple locations
> within VACUUM
> http://archives.postgresql.org/pgsql-patches/2007-05/msg00143.php
>
> Great, but let's link to this more recent thread instead:
> https://www.postgresql.org/message-id/flat/CAD21AoAfOZvmfR0j8VmZorZjL7RhTiQdVttNuC4W-Shdc2a-AA%40mail.gmail.com

Done.

> > The second thread is really about autovacuum launcher scheduling.
> > Probably still relevant, but the thread is very long and doesn't seem
> > terribly helpful to someone trying to get up to speed on the issues
> > that are still relevant. I don't see any more recent discussion,
> > either. Thoughts?

Split into two entries.

On Wed, Dec 8, 2021 at 8:12 PM Masahiko Sawada <sawada.mshk@gmail.com> wrote:
> There is another discussion on autovacuum scheduling in 2018 here:
>
> https://www.postgresql.org/message-id/0A3221C70F24FB45833433255569204D1F8A4DC6%40G01JPEXMBYT05
>
> Some algorithms were proposed there and I implemented a PoC patch:
>
> https://www.postgresql.org/message-id/CAD21AoBUaSRBypA6pd9ZD%3DU-2TJCHtbyZRmrS91Nq0eVQ0B3BA%40mail.gmail.com

Added, thanks!

--
John Naylor
EDB: http://www.enterprisedb.com