Il 26/mar/2014 13:36 "Ilya Kosmodemiansky" < ilya.kosmodemian...@postgresql-consulting.com> ha scritto: > > Hi Alexey, > > On Wed, Mar 26, 2014 at 1:21 PM, Alexey Vasiliev <leopard...@inbox.ru> wrote: > > I read from several sources, what maximum shared_buffers is 8GB. > > I believe that was an issue on some older versions, and thats why was > mentioned in several talks. Today it is a sort of apocrypha. > > > Does this true? If yes, why exactly this number is maximum number of > > shared_buffers for good performance (on Linux 64-bits)? > > 25% of available RAM is a good idea to start. Sometimes, if you have > heavy workload _and_ it is possible to reside whole database in > memory, better to use something larger, about ~75% of RAM. > > Best regards, > Ilya > -- > Ilya Kosmodemiansky, > > PostgreSQL-Consulting.com > tel. +14084142500 > cell. +4915144336040 > i...@postgresql-consulting.com > > > -- > Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) > To make changes to your subscription: > http://www.postgresql.org/mailpref/pgsql-performance
max is 1024mb. you have to test your workload if it's too low you will get too much i/o ( the filesystem cache could help.. not always /*nfs*/), if too high your cpu will be eated by lru/ latch/ and so on. Mat Dba
