2010/2/6 BillR <iambill@xxxxxxxxxxxxxxxxx>: > I don't know how to do this with PostgreSQL, but I am pretty sure what > Alexei is looking for is what Oracle and SQL Server people refer to as > 'pinning' a table or other DB object (into memory). I would be interested to > know if PostgreSQL does this too. I think it is a very useful feature. > > How to pin a table in cache with Oracle (for an example): > http://www.jlcomp.demon.co.uk/faq/pin_table.html > > Couple more examples. > > http://blogs.oracle.com/stevenChan/2007/05/pinning_objects_to_improve_app.ht > ml > > http://www.mssqltips.com/tip.asp?tip=1317 > > In some large enterprise systems I have worked on (e.g. tier one telecom > companies), besides the standard Oracle installation the billing systems > used one database product where everything was in memory. This was used > *mostly* for static lookup data to help speed up the performance of the > system. When you have say, 300 million customers, every little bit helps. :) > > Hopefully someone knows how with Postgres. In some way pgfincore let you do that with function pgfadv_willneed(table/index). It will try to load blocks of the relations without killing your IO. But, I am not sure it is the correct answer for the problem here. > > Cheers > > -----Original Message----- > From: pgsql-general-owner@xxxxxxxxxxxxxx > [mailto:pgsql-general-owner@xxxxxxxxxxxxxx] On Behalf Of Bret S. Lambert > Sent: February-06-10 4:50 AM > To: Alexei Vladishev > Cc: pgsql-general@xxxxxxxxxxxxxx > Subject: Re: Multiple buffer cache? > > 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. > >> >> 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 > > -------------------------------- > Spam/Virus scanning by CanIt Pro > > For more information see > http://www.kgbinternet.com/SpamFilter.htm > > To control your spam filter, log in at > http://filter.kgbinternet.com > > > -- > BEGIN-ANTISPAM-VOTING-LINKS > ------------------------------------------------------ > > Teach CanIt if this mail (ID 80190050) is spam: > Spam: > http://filter.kgbinternet.com/canit/b.php?i=80190050&m=fbb7172fd677&t=201002 > 06&c=s > Not spam: > http://filter.kgbinternet.com/canit/b.php?i=80190050&m=fbb7172fd677&t=201002 > 06&c=n > Forget vote: > http://filter.kgbinternet.com/canit/b.php?i=80190050&m=fbb7172fd677&t=201002 > 06&c=f > ------------------------------------------------------ > END-ANTISPAM-VOTING-LINKS > > __________ Information from ESET Smart Security, version of virus signature > database 4841 (20100206) __________ > > The message was checked by ESET Smart Security. > > http://www.eset.com > > > > > -- > Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) > To make changes to your subscription: > http://www.postgresql.org/mailpref/pgsql-general > -- Cédric Villemain -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
