Le Thursday 16 July 2009 22:07:25, Kevin Grittner a écrit : > Marc Cousin <cousinmarc@xxxxxxxxx> wrote: > > the hot parts of these 2 tables are extremely likely to be in the > > database or linux cache (buffer hit rate was 97% in the example > > provided). Moreover, the first two queries of the insert procedure > > fill the cache for us... > > This would be why the optimizer does the best job estimating the > relative costs of various plans when you set the random_page_cost and > seq_page_cost very low. > > -Kevin Ok, so to sum it up, should I keep these values (I hate doing this :) ) ? Would there be a way to approximately evaluate them regarding to the expected buffer hit ratio of the query ? -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
