Re: [PERFORM] Hardware suggestions for maximum read performance

2013-05-02 Thread Arjen van der Meijden
3x200GB suggests you want to use RAID5? Perhaps you should just pick 2x200GB and set them to RAID1. With roughly 200GB of storage, that should still easily house your "potentially 10GB"-database with ample of room to allow the SSD's to balance the writes. But you save the investment and its pr

Re: [PERFORM] Hardware suggestions for maximum read performance

2013-05-02 Thread Scott Marlowe
On Thu, May 2, 2013 at 5:11 PM, Mike McCann wrote: > Hello, > > We are in the fortunate situation of having more money than time to help > solve our PostgreSQL 9.1 performance problem. > > Our server hosts databases that are about 1 GB in size with the largest > tables having order 10 million 20-b

[PERFORM] Hardware suggestions for maximum read performance

2013-05-02 Thread Mike McCann
Hello, We are in the fortunate situation of having more money than time to help solve our PostgreSQL 9.1 performance problem. Our server hosts databases that are about 1 GB in size with the largest tables having order 10 million 20-byte indexed records. The data are loaded once and then read f

Re: [PERFORM] In progress INSERT wrecks plans on table

2013-05-02 Thread mark . kirkwood
> mark.kirkw...@catalyst.net.nz wrote on 03.05.2013 00:19: >> I think the idea of telling postgres that we are doing a load is >> probably >> the wrong way to go about this. We have a framework that tries to >> automatically figure out the best plans...I think some more thought >> about >> how to m

Re: [PERFORM] In progress INSERT wrecks plans on table

2013-05-02 Thread Thomas Kellerer
mark.kirkw...@catalyst.net.nz wrote on 03.05.2013 00:19: I think the idea of telling postgres that we are doing a load is probably the wrong way to go about this. We have a framework that tries to automatically figure out the best plans...I think some more thought about how to make that understan

Re: [PERFORM] In progress INSERT wrecks plans on table

2013-05-02 Thread mark . kirkwood
> On 2 May 2013 01:49, Mark Kirkwood wrote: > > I think we need a problem statement before we attempt a solution, > which is what Tom is alluding to. > Actually no - I think Tom (quite correctly) was saying that the patch was not a viable solution. With which I agree. I believe the title of this

Re: [PERFORM] "WHERE 1 = 2 OR ..." makes planner choose a very inefficient plan

2013-05-02 Thread Claudio Freire
On Thu, May 2, 2013 at 9:48 AM, Simon Riggs wrote: >>> SELECT count(k0.id) >>> FROM k0 >>> WHERE 1 = 2 >>> OR k0.id IN ( >>> SELECT k1.k0_id >>> FROM k1 >>> WHERE k1.k1k2_id IN ( >>> SELECT k2.k1k2_id >>> FROM k2 >>> WHERE

Re: [PERFORM] "WHERE 1 = 2 OR ..." makes planner choose a very inefficient plan

2013-05-02 Thread Simon Riggs
On 18 April 2013 15:46, Tom Lane wrote: > dmitry potapov writes: >> I recently stumbled upon on what could be a planner bug or a corner case. >> If " OR ..." is added to WHERE clause of SELECT query, >> then the planner chooses a very inefficient plan. Consider a query: > >> SELECT count(k0.id) >

Re: [PERFORM] Query planner ignoring constraints on partitioned tables when joining

2013-05-02 Thread Simon Riggs
On 18 April 2013 22:42, Tom Lane wrote: > One could imagine adding planner logic that would make inferences of a > similar sort for equalities combined with inequalities, but it would be > vastly more complicated, and would provide useful results in vastly > fewer queries, than the equality-propa

Re: [PERFORM] In progress INSERT wrecks plans on table

2013-05-02 Thread Simon Riggs
On 2 May 2013 01:49, Mark Kirkwood wrote: > On 02/05/13 02:06, Tom Lane wrote: >> >> Mark Kirkwood writes: >>> >>> I am concerned that the deafening lack of any replies to my original >>> message is a result of folk glancing at your original quick reply and >>> thinking... incomplete problem spec