On Sat, Feb 06, 2010 at 02:44:32PM +0100, C?dric Villemain wrote: > 2010/2/6 Bret S. Lambert <bret.lambert@xxxxxxxxx>: > > On Fri, Feb 05, 2010 at 11:41:13PM +0200, Alexei Vladishev wrote: > >> Greetings, > >> > >> Is there a way of configuring PostgreSQL so that one specific table would > >> use, say, 4GB of buffer cache while other tables would use the rest? > >> > >> I would like to keep the table and its indexes always in "hot" > >> state, so that > >> other queries won't pollute this part of the buffer cache. It would ensure > >> reliable performance and much less disk IOPS working with the table. > > > > Fiddling with the buffer cache like that would require some sort of > > OS support, if I'm not mistaken in what you're asking for. > > > > And then, even if the support is there, you'd need to outline exactly > > how you're planning on pushing this button. > > > > Specifically, what's your usage pattern that would make this a > > win for you? > > > > If the table and its indexes can already fit into the buffer cache, > > and it's as commonly accessed as you think it is, the OS should > > probably have it cached anyway. > > that's all true. > > I am working on pgfincore which allow in some way to prepare buffer cache. > You need pg > 8.4 and linux (probably working with bsd too) Why do something with a non-portable interface? Most OSes support coherently mmap(2)'ing disk blocks into memory; in fact, I'm somewhat taken aback that the postgres buffer cache isn't implemented in that manner, but I'm willing to give the devs credit for having not done so for good reasons. > > I don't consider it ready fo rproduction, but fine for debugging > things, if you reall care the buffer cache preload, tell me, I'll > stabilize the code in a shorter time ;) > http://villemain.org/projects/pgfincore > > > > >> > >> Is it possible? > >> > >> Thanks for any hints! > >> > >> Alexei > >> > >> -- > >> Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) > >> To make changes to your subscription: > >> http://www.postgresql.org/mailpref/pgsql-general > > > > -- > > Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) > > To make changes to your subscription: > > http://www.postgresql.org/mailpref/pgsql-general > > > > > > -- > C?dric Villemain -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
