Re: random_page_cost = 2.0 on Heroku Postgres

Hmm, perhaps we could usefully aggregate auto_explain output.

On Thu, Feb 9, 2012 at 7:32 AM, Jeff Janes <jeff.janes@gmail.com> wrote:
> On Wed, Feb 8, 2012 at 6:28 PM, Scott Marlowe <scott.marlowe@gmail.com> wrote:
>> On Wed, Feb 8, 2012 at 6:45 PM, Peter van Hardenberg <pvh@pvh.ca> wrote:
>>> Having read the thread, I don't really see how I could study what a
>>> more principled value would be.
>>
>> Agreed.  Just pointing out more research needs to be done.
>>
>>> That said, I have access to a very large fleet in which to can collect
>>> data so I'm all ears for suggestions about how to measure and would
>>> gladly share the results with the list.
>>
>> I wonder if some kind of script that grabbed random queries and ran
>> them with explain analyze and various random_page_cost to see when
>> they switched and which plans are faster would work?
>
> But if you grab a random query and execute it repeatedly, you
> drastically change the caching.
>
> Results from any execution after the first one are unlikely to give
> you results which are meaningful to the actual production situation.
>
> Cheers,
>
> Jeff



--
Peter van Hardenberg
San Francisco, California
"Everything was beautiful, and nothing hurt." -- Kurt Vonnegut