On Thu, Aug 17, 2006 at 01:47:37PM -0400, Matthew T. O'Connor wrote: > Alvaro Herrera wrote: > >Matthew T. O'Connor wrote: > > > >>I assume you are suggesting that the base value be 0? Well for one > >>thing if the table doesn't have any rows that will result in constant > >>vacuuming of that table, so it needs to be greater than 0. For a small > >>table, say 100 rows, there usually isn'tn much performance impact if the > >>table if 50% dead space, so I think the base values you suggest are OK, > >>but they shouldn't be 0. > >> > > > >Actually Tom suggested some time ago that we should get rid of the base > >value completely, i.e. make it 0 forever. > > > >A row with 0 tables would not show any activity in pgstats, so it would > >not be vacuumed constantly. Only once after it's truncated. > > OK, forgot that. Well I put it in originally as a way to give more > flexability to the calculation, if I want a tabled vacuumed every 100 > updates, then I can set the scaling factor to 0 and the base value to > 100, but maybe that's not really needed. It would simplify things if we > got rid of it.
I think it makes more sense in the per-table settings (which I can't remember if we actually have yet). For example, on a frequently update table that you know should always be small, you might well want to set it to scaling factor 0 and base of 20 or whatever. -- Jim C. Nasby, Sr. Engineering Consultant [EMAIL PROTECTED] Pervasive Software http://pervasive.com work: 512-231-6117 vcard: http://jim.nasby.net/pervasive.vcf cell: 512-569-9461 ---------------------------(end of broadcast)--------------------------- TIP 4: Have you searched our list archives? http://archives.postgresql.org