Re: our checks for read-only queries are not great

On Tue, Jan 14, 2020 at 1:46 PM Stephen Frost <sfrost@snowman.net> wrote:
> * Tom Lane (tgl@sss.pgh.pa.us) wrote:
> > Robert Haas <robertmhaas@gmail.com> writes:
> > > Speaking of sensible progress, I think we've drifted off on a tangent
> > > here about ALTER SYSTEM.
> >
> > Agreed, that's not terribly relevant for the proposed patch.
>
> I agree that the proposed patch seems alright by itself, as the changes
> it's making to existing behavior seem to all be bug-fixes and pretty
> clear improvements not really related to 'read-only' transactions.

There seems to be no disagreement on this point, so I have committed the patch.

> It's unfortunate that we haven't been able to work through to some kind
> of agreement around what "SET TRANSACTION READ ONLY" means, so that
> users of it can know what to expect.

I at least feel like we have a pretty good handle on what it was
intended to mean; that is, "doesn't cause semantically significant
changes to pg_dump output." I do hear some skepticism as to whether
that's the best definition, but it has pretty good explanatory power
relative to the current state of the code, which is something.

-- 
Robert Haas
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