Re: Prepared transactions vs novice DBAs, again

"Joshua D. Drake" <jd@commandprompt.com> writes:
> On Wed, 2009-04-22 at 15:49 -0400, Tom Lane wrote:
>> Comments?  Anyone seriously opposed to making the default be zero?

> I am not opposed to making the default zero. I am also +1 on adding the
> warnings.

What I think we could/should do about that for 8.4 is to improve the
HINTs associated with the impending-wraparound warnings in varsup.c,
so that they mention cleaning out old prepared transactions as another
thing you might need to do.  A more extensive solution --- in
particular, adding warnings that occur at some lower threshold than
the wraparound warnings --- seems to me to require more changes than
we should consider post-beta.  It might be worth working on for 8.5
though.

(In case it's not clear, I'm envisioning changing the
max_prepared_transactions default for 8.4.  It won't be a big change
if we do it as Heikki suggests.)
        regards, tom lane