Re: Let's make PostgreSQL multi-threaded

On Mon, Jun 5, 2023 at 10:52 AM Heikki Linnakangas <hlinnaka(at)iki(dot)fi> wrote:
> I spoke with some folks at PGCon about making PostgreSQL multi-threaded,
> so that the whole server runs in a single process, with multiple
> threads. It has been discussed many times in the past, last thread on
> pgsql-hackers was back in 2017 when Konstantin made some experiments [0].
>
> I feel that there is now pretty strong consensus that it would be a good
> thing, more so than before. Lots of work to get there, and lots of
> details to be hashed out, but no objections to the idea at a high level.

I'm not sure that there's a strong consensus, but I do think it's a good idea.

> # Transition period
>
> The transition surely cannot be done fully in one release. Even if we
> could pull it off in core, extensions will need more time to adapt.
> There will be a transition period of at least one release, probably
> more, where you can choose multi-process or multi-thread model using a
> GUC. Depending on how it goes, we can document it as experimental at first.

I think the transition period should probably be effectively infinite.
There might be some distant future day when we'd remove the process
support, if things go incredibly well with threads, but I don't think
it would be any time soon. If nothing else, considering that we don't
want to force a hard compatibility break for extensions.

--
Robert Haas
EDB: http://www.enterprisedb.com