On Wed, Aug 23, 2006 at 01:45:43PM +0900, ITAGAKI Takahiro wrote: > > "Jim C. Nasby" <[EMAIL PROTECTED]> wrote: > > > And +1 on Rod's suggestion to make it more aggressive. I always drop the > > scale factor to at least 0.2 and 0.1 (though 0.1 and 0.05 don't seem > > unreasonable), and typically drop the thresholds to 200 and 100 (though > > again, lower is probably warrented). > > The default fillfactors for index btree is 90%. So if we want to avoid > spliting of the leaf pages, vacuum scale factors should be less than 0.1 > in cases where tuples are only updated randomly. I think threshoulds should > be less than PCTFREEs(=1-fillfactors) except ever-increasing tables.
Very good point, though at least for indexes the new code that tries to reclaim space on a page before splitting it will help. Doesn't help for the heap, though. So maybe the default should be 0.08? -- 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
