On Tue, Oct 04, 2005 at 07:33:47PM -0400, Ron Peacetree wrote: > pg is _very_ stupid about caching. Almost all of the caching is left > to the OS, and it's that way by design (as post after post by TL has > pointed out). > > That means pg has almost no ability to take application domain > specific knowledge into account when deciding what to cache. > There's plenty of papers on caching out there that show that > context dependent knowledge leads to more effective caching > algorithms than context independent ones are capable of. > > (Which means said design choice is a Mistake, but unfortunately > one with too much inertia behind it currentyl to change easily.) > > Under these circumstances, it is quite possible that an expert class > human could optimize memory usage better than the OS + pg.
Do you have any examples where this has actually happened? Especially with 8.x, which isn't all that 'stupid' about how it handles buffers? -- 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 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
