Re: Very big insert/join performance problem (bacula)

Le Thursday 16 July 2009 22:07:25, Kevin Grittner a écrit :
> Marc Cousin <cousinmarc@gmail.com> 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 ?