Re: Allow single table VACUUM in transaction block

On Thu, 17 Nov 2022 at 20:06, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
>
> On Wed, Nov 16, 2022 at 5:14 PM Greg Stark <stark(at)mit(dot)edu> wrote:
> > However I'm not a fan of commands that sometimes do one thing and
> > sometimes magically do something very different. I don't like the idea
> > that the same vacuum command would sometimes run in-process and
> > sometimes do this out of process request. And the rules for when it
> > does which are fairly complex to explain -- it runs in process unless
> > you're in a transaction when it runs out of process unless it's a
> > temporary table ...
>
> 100% agree.

I agree as well.

At the moment, the problem (OT) is that VACUUM behaves inconsistently

Outside a transaction - works perfectly
In a transaction - throws ERROR, which prevents a whole script from
executing correctly

What we are trying to do is avoid the ERROR. I don't want them to
behave like this, but that's the only option possible to avoid ERROR.

So if consistency is also a strong requirement, then maybe we should
make that new command the default, i.e. make VACUUM always just a
request to vacuum in background. That way it will be consistent.

Can we at least have a vacuum_runs_in_background = on | off, to allow
users to take advantage of this WITHOUT needing to rewrite all of
their scripts?

--
Simon Riggs http://www.EnterpriseDB.com/