On Mon, Aug 16, 2010 at 3:01 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Greg Smith <greg@2ndquadrant.com> writes:
>> Tom Lane wrote:
>>> On versions where autovacuum is on by default, I would certainly
>>> recommend trying to use only autovacuum. cron-driven vacuum still
>>> has some uses but they are corner cases.
>
>> Corner cases implies something a bit more rare than I'd consider the
>> case here.
>
> Well, it certainly has some uses, but I still think it's good advice to
> first see if autovac alone will keep you happy.
>
>> The other alternative here is to just tune autovacuum so it runs really
>> slowly, so it won't kill responsiveness during any peak period. While
>> in theory that's the right thing to do, this is much harder to get
>> working well than what I just described.
>
> But you really have to do that *anyway*, if you're not going to turn
> autovac off.
>
> I think the case where you want to combine cron-driven vacuum with
> autovac is where, having made sure autovac is dialed down enough to not
> present performance issues, you find that it can't keep up with the
> required vacuuming. Then you need to do some not-hobbled vacuuming
> during your maintenance windows. Eventually probably autovac will have
> some understanding of maintenance windows built-in, but it doesn't yet.
For this application (and most of my databases), I'm fairly certain
that autovacuum will work fine on its own. I'm going to disable the
cron-vacuuming and try running with autovacuum alone.
Thanks for the help,
Peter
