Re: Unhappy about API changes in the no-fsm-for-small-rels patch

Amit Kapila <amit.kapila16@gmail.com>

From: Amit Kapila <amit.kapila16@gmail.com>

To: John Naylor <john.naylor@2ndquadrant.com>

Cc: Tom Lane <tgl@sss.pgh.pa.us>, Andres Freund <andres@anarazel.de>, PostgreSQL-development <pgsql-hackers@postgresql.org>

Date: 2019-04-22T13:19:44Z

Lists: pgsql-hackers

Attachments

store_local_map_relcache_v1.patch (application/octet-stream) patch v1

On Fri, Apr 19, 2019 at 2:46 PM Amit Kapila <amit.kapila16@gmail.com> wrote:
>
>
> > > I am thinking that we should at least give it a try to move the map to
> > > rel cache level to see how easy or difficult it is and also let's wait
> > > for a day or two to see if Andres/Tom has to say anything about this
> > > or on the response by me above to improve the current patch.
> >
> > Since we have a definite timeline, I'm okay with that, although I'm
> > afraid I'm not quite knowledgeable enough to help much with the
> > relcache piece.
> >
>
> Okay, I can try to help.  I think you can start by looking at
> RelationData members (for ex. see how we cache index's metapage in
> rd_amcache) and study a bit about routines in relcache.h.
>

Attached is a hacky and work-in-progress patch to move fsm map to
relcache.  This will give you some idea.  I think we need to see if
there is a need to invalidate the relcache due to this patch.  I think
some other comments of Andres also need to be addressed, see if you
can attempt to fix some of them.

-- 
With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com

Commits

Revert "Avoid the creation of the free space map for small heap relations".
- 7db0cde6b58e 12.0 landed
Improve code comments in b0eaa4c51b.
- 06c8a5090ed9 12.0 cited
During pg_upgrade, conditionally skip transfer of FSMs.
- 13e8643bfc29 12.0 cited
Add more tests for FSM.
- 6f918159a97a 12.0 cited
Fix typos in commit 8586bf7ed8.
- a6e48da08844 12.0 cited
tableam: introduce table AM infrastructure.
- 8586bf7ed888 12.0 cited
Clear the local map when not used.
- 9c32e4c35026 12.0 cited
Doc: Update the documentation for FSM behavior for small tables.
- 29d108cdecbe 12.0 cited
Make FSM test portable.
- 08ecdfe7e5e0 12.0 cited
Avoid creation of the free space map for small heap relations, take 2.
- b0eaa4c51bbf 12.0 cited