One way of tracking changes would be a last_change
date field which would be updated every time a row was
updated. Of course, if the database is big enough
that your worried about resource utilization by
vacuum, then you might not like the additional space
consumption of a purely administrative field.
Best of luck,
Andrew Gould
--- "Roderick A. Anderson" <raanders@tincan.org>
wrote:
> On Fri, 7 Dec 2001, Jan Wieck wrote:
>
> > The question how often to vacuum depends on
> the database use.
> > As a rule of thumb I'd suggest start with
> vacuuming when
> > approx. 10-30% of the data has been touched
> (UPDATED/DELETED)
>
> Which brings up an interesting thought. Is there
> any way to query the
> databae and find out how much data has been
> 'CHANGED' since the last
> vacuum? I don't remember seeing any mention of this
> for a year or
> longer in either GENERAL or HACKERS.
> If there is or could be, a low usage database
> could be probed and
> then vacumm run if needed. Not sure if the CPU
> cycles to run the cron
> job and query are lower than the 'just do it' on a
> set schedule would
> be.
>
>
> Cheers,
> Rod
> --
> Let Accuracy Triumph Over
> Victory
>
>
> Zetetic Institute
>
> "David's Sling"
>
> Marc Stiegler
>
>
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