> Just moving from 7.1 to 7.4 should help, since you can start using plain
> vacuum (7.1's vacuum is equivalent to vacuum full IIRC).
That old DB server has been running contnuously for 2 years they tell me.
Apparently it is also growing despite nightly vacuums and a stable data set
size (old data is purged dai.ly and monthly). Nightly delete/insert batches
and vacuums are taking longer and longer too. I suspect the vacuum isn't
doing what they think - possibly due to the FSM being at the default, and
possibly due to ghost processes holding old record versions open. It has
been stable nonetheless. Anyway, I'm sure we can do much better in 7.4.
> > If I start a VACUUM FULL, is it ok to interrupt it part way through? I
mean,
> > is a partially completed vacuum full worth anything, and is there any
danger
> > in routinely killing it?
>
> It's crash-safe but you may leave your indexes bigger than before :-(
OK, that's the kind of thing I wanted to know. Basically, partial runs of
vacuum full are not likely to be of any benefit. So, unless you intend to
let it run to completion, best to avoid it.
Given that our system experiences quite heavy usage during the day, and has
a nightly window for batch processing I'm wondering if the best way to go
about this is to give auto vacuum a miss and just do a standard vacuum after
the batch processes have completed. As long as the FSM is big enough to
handle the amount of data changed in 1 day, it would be OK, right?
Thanks for the input, (and Bruno too)
Iain