Re: [PERFORM] Partition table in 9.0.x?

2013-01-14 Thread Jeff Janes
On Tue, Jan 8, 2013 at 10:04 AM, AJ Weber wrote: >> >> The current constraint exclusion code is quite simple-minded and >> doesn't know how to make use of check constraints that use the mod >> function, so the indexes of all partitions would have to be searched >> for each order_num-driven query,

Re: [PERFORM] Two Necessary Kernel Tweaks for Linux Systems

2013-01-14 Thread Boszormenyi Zoltan
2013-01-08 22:48 keltezéssel, Shaun Thomas írta: On 01/08/2013 02:05 PM, AJ Weber wrote: Is there an "easy" way to tell what scheduler my OS is using? Unfortunately not. I looked again, and it seems that CFS was merged into 2.6.23. Anything before that is probably safe, but the vendor may ha

Re: [PERFORM] serious under-estimation of n_distinct for clustered distributions

2013-01-14 Thread Peter Geoghegan
On 14 January 2013 07:35, Stefan Andreatta wrote: > The source of these troubles is the sampling method employed in > src/backend/commands/analyze.c. Judging from Tom Lane's comment for the > original implementation in 2004 this has never been thought to be perfect. > Does anybody see a chance to