Re: Statement timeout behavior in extended queries

On 2017-04-04 16:38:53 -0700, Andres Freund wrote:
> On 2017-04-04 16:10:32 +0900, Tatsuo Ishii wrote:
> > >> If what Tatsuo-san said to Tom is correct (i.e. each Parse/Bind/Execute starts and stops the timer), then it's a concern and the patch should not be ready for committer. However, the current patch is not like that -- it seems to do what others in this thread are expecting.
> > >
> > > Oh, interesting - I kind of took the author's statement as, uh,
> > > authoritative ;). A quick look over the patch confirms your
> > > understanding.
> >
> > Yes, Tsunakawa-san is correct. Sorry for confusion.
> >
> > > I think the code needs a few clarifying comments around this, but
> > > otherwise seems good. Not restarting the timeout in those cases
> > > obviously isn't entirely "perfect"/"correct", but a tradeoff - the
> > > comments should note that.
> > >
> > > Tatsuo-san, do you want to change those, and push? I can otherwise.
> >
> > Andres,
> >
> > If you don't mind, could you please fix the comments and push it.
>
> Hm. I started to edit it, but I'm halfway coming back to my previous
> view that this isn't necessarily ready.
>
> If a client were to to prepare a large number of prepared statements
> (i.e. a lot of parse messages), this'll only start the timeout once, at
> the first statement sent. It's not an issue for libpq which sends a
> sync message after each PQprepare, nor does it look to be an issue for
> pgjdbc based on a quick look.
>
> Does anybody think there might be a driver out there that sends a bunch
> of 'parse' messages, without syncs?

Looks to me like npgsql doesn't do that either. None of libpq, pgjdbs
and npgsql doing it seems like some evidence that it's ok.

- Andres