Re: Abnormal performance difference between Postgres and MySQL

Kevin Grittner wrote:
>>>> Farhan Husain <russoue@gmail.com> wrote:
>> Thanks a lot Scott! I think that was the problem. I just changed the
>> default statistics target to 50 and ran explain. The plan changed
>> and I ran explain analyze. Now it takes a fraction of a second!
>
> Yeah, the default of 10 has been too low.  In 8.4 it is being raised
> to 100.
>
>> Thanks to all of you who wanted to help me. I would be happy if
>> someone does me one last favor. I want to know how these query plans
>> are generated and how the parameters you suggested to change affects
>> it. If there is any article, paper or book on it please give me the
>> name or url.
>
> In terms of tuning in general, you might start with these:
>
> http://wiki.postgresql.org/wiki/Tuning_Your_PostgreSQL_Server
>
> http://www.postgresql.org/docs/8.3/interactive/runtime-config-query.html
>
> To understand the mechanics of the optimizer you might be best off
> downloading the source code and reading through the README files and
> comments in the source code.
>
> -Kevin
>
Hello List,

Can this be set in the postgresql.conf file?
default_statistics_target = 50

Thanks,
Steve