David Lang wrote:
> On Fri, 16 Dec 2005, Mark Kirkwood wrote:
>
>>
>> Right on. Some of these "coerced" plans may perform much better. If
>> so, we can look at tweaking your runtime config: e.g.
>>
>> effective_cache_size
>> random_page_cost
>> default_statistics_target
>>
>> to see if said plans can be chosen "naturally".
>
>
> Mark, I've seen these config options listed as tweaking targets fairly
> frequently, has anyone put any thought or effort into creating a test
> program that could analyse the actual system and set the defaults based
> on the measured performance?
>
I am sure this has been discussed before, I found this thread -
http://archives.postgresql.org/pgsql-performance/2004-07/msg00189.php
but I seem to recall others (but offhand can't find any of them).
I think that the real difficultly here is that the construction of the
test program is non trivial - for instance, the best test program for
tuning *my* workload is my application with its collection of data, but
it is probably not a good test program for *anyone else's* workload.
cheers
Mark