Re: BUG #5946: Long exclusive lock taken by vacuum (not full)

Christopher Browne <cbbrowne(at)gmail(dot)com> writes:
> On Fri, Mar 25, 2011 at 11:17 AM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>> Use autovacuum --- if there's something that wants to access the table,
>> autovac will get kicked off the lock. (Of course, the table may never
>> get truncated then, but maybe you don't care.)

> I could see this turning out somewhat unhappily...

> If there's almost always something that wants to access the table,
> which would be hardly surprising, in view that the table is being
> updated with sufficient regularity that it's got 10GB+ of dead space
> at the end, then you're eventually going to *HAVE* to vacuum it.
> Transaction rollover, and what not.

It is already vacuumed. The only remaining step is to release free
space back to the OS; and if he's got a lot of churn in the table,
it's not entirely clear that that's a productive activity anyway.

regards, tom lane