On Wed, Feb 8, 2012 at 6:28 PM, Scott Marlowe <[email protected]> wrote: > On Wed, Feb 8, 2012 at 6:45 PM, Peter van Hardenberg <[email protected]> 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 -- Sent via pgsql-performance mailing list ([email protected]) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
