On Fri, Nov 18, 2011 at 3:09 AM, Greg Smith <greg@xxxxxxxxxxxxxxx> wrote: > On 11/17/2011 10:44 PM, CSS wrote: >> >> Is there any sort of simple documentation on the query planner that might >> cover how things like increased RAM could impact how a query is executed? > > There is no *simple* documentation on any part of the query planner that's > also accurate. Query planning is inherently complicated. > > I think this point wasn't quite made clearly. PostgreSQL has no idea how > much memory is in your system; it doesn't try to guess or detect it. effective_cache_size tells the db how much memory you have. Since you have to set it, it can be anything you want, but if you've set it to something much higher on the new machine then it can affect query planning. -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
