Re: [PERFORM] suggestions for postgresql setup on Dell 2950 , PERC6i controller

2009-02-05 Thread Matt Burke
Arjen van der Meijden wrote: Afaik the Perc 5/i and /e are more or less rebranded LSI-cards (they're not identical in layout etc), so it would be a bit weird if they performed much less than the similar LSI's wouldn't you think? I've recently had to replace a PERC4/DC with the exact same card

Re: [PERFORM] suggestions for postgresql setup on Dell 2950 , PERC6i controller

2009-02-06 Thread Matt Burke
Rajesh Kumar Mallah wrote: I've checked out the latest Areca controllers, but the manual available on their website states there's a limitation of 32 disks in an array... Where exactly is there limitation of 32 drives. the datasheet of 1680 states support upto 128drives using

Re: [PERFORM] suggestions for postgresql setup on Dell 2950 , PERC6i controller

2009-02-06 Thread Matt Burke
Scott Carey wrote: You probably don’t want a single array with more than 32 drives anyway, its almost always better to start carving out chunks and using software raid 0 or 1 on top of that for various reasons. I wouldn’t put more than 16 drives in one array on any of these RAID cards, they’re

Re: [PERFORM] suggestions for postgresql setup on Dell 2950 , PERC6i controller

2009-02-06 Thread Matt Burke
Glyn Astill wrote: Stupid question, but why do people bother with the Perc line of cards if the LSI brand is better? It seems the headache of trying to get the Perc cards to perform is not worth any money saved. I think in most cases the dell cards actually cost more, people end up stuck

Re: [PERFORM] Slow-ish Query Needs Some Love

2010-02-02 Thread Matt White
On Feb 2, 6:06 am, Edgardo Portal egportal2...@yahoo.com wrote: On 2010-02-02, Matt White mattw...@gmail.com wrote: I have a relatively straightforward query that by itself isn't that slow, but we have to run it up to 40 times on one webpage load, so it needs to run much faster than

[PERFORM] Slow-ish Query Needs Some Love

2010-02-02 Thread Matt White
I have a relatively straightforward query that by itself isn't that slow, but we have to run it up to 40 times on one webpage load, so it needs to run much faster than it does. Here it is: SELECT COUNT(*) FROM users, user_groups WHERE users.user_group_id = user_groups.id AND NOT users.deleted

[PERFORM] Slowing UPDATEs inside a transaction

2011-03-03 Thread Matt Burke
Hi. I've only been using PostgreSQL properly for a week or so, so I apologise if this has been covered numerous times, however Google is producing nothing of use. I'm trying to import a large amount of legacy data (billions of denormalised rows) into a pg database with a completely different

Re: [PERFORM] Slowing UPDATEs inside a transaction

2011-03-04 Thread Matt Burke
Robert Haas wrote: Old row versions have to be kept around until they're no longer of interest to any still-running transaction. Thanks for the explanation. Regarding the snippet above, why would the intermediate history of multiply-modified uncommitted rows be of interest to anything, or is

[PERFORM] Performance of Seq Scan from buffer cache

2012-08-21 Thread Matt Daw
reasonable (8644.1985 MB/s with 1 core - 25017 MB/s with 12 cores). The box is running 2.6.26.6-49 and postgresql 9.0.6. I'm stumped as to why it's so much slower, any ideas on what might explain it… or other benchmarks I could run to try to narrow down the cause? Thanks! Matt

Re: [PERFORM] Performance of Seq Scan from buffer cache

2012-08-21 Thread Matt Daw
..94459.07 rows=1926207 width=0) (actual time=0.005..1475.218 rows=1926207 loops=1) Total runtime: 2889.360 ms (3 rows) Time: 2889.842 ms On Tuesday, 21 August, 2012 at 3:57 PM, Matt Daw wrote: Howdy. I'm curious what besides raw hardware speed determines the performance of a Seq Scan

[PERFORM] Query plan, nested EXISTS

2012-09-28 Thread Matt Daw
why this plan is being chosen? Thanks! Matt

Re: [PERFORM] Query plan, nested EXISTS

2012-09-28 Thread Matt Daw
Hi Tom, thank you very much. I'll load these tables onto a 9.2 instance and report back. Matt On Fri, Sep 28, 2012 at 2:44 PM, Tom Lane t...@sss.pgh.pa.us wrote: Matt Daw m...@shotgunsoftware.com writes: Howdy, I've been debugging a client's slow query today and I'm curious about the query

Re: [PERFORM] Query plan, nested EXISTS

2012-09-28 Thread Matt Daw
%'::text)) Rows Removed by Filter: 1 Total runtime: 147.411 ms (14 rows) On Fri, Sep 28, 2012 at 2:47 PM, Matt Daw m...@shotgunsoftware.com wrote: Hi Tom, thank you very much. I'll load these tables onto a 9.2 instance and report back. Matt On Fri, Sep 28, 2012 at 2:44 PM

[PERFORM] Estimation question...

2013-02-26 Thread Matt Daw
getting a bad estimate. Is this an expected result? Thanks! Matt = 1) Filter on project_id only, row estimate for Bitmap Index Scan quite good. explain (analyze,buffers) select count(id) from versions WHERE project_id=115; QUERY PLAN

Re: [PERFORM] Estimation question...

2013-02-27 Thread Matt Daw
own. Matt On Tue, Feb 26, 2013 at 11:35 AM, Matt Daw m...@shotgunsoftware.com wrote: Howdy, the query generator in my app sometimes creates redundant filters of the form: project_id IN ( list of projects user has permission to see ) AND project_id = single project user is looking

Re: [PERFORM] Estimation question...

2013-02-28 Thread Matt Daw
/9.0/static/row-estimation-examples.html was a big help. Matt On Wed, Feb 27, 2013 at 9:08 AM, Matt Daw m...@shotgunsoftware.com wrote: Quick follow up... I've found that the row estimate in: explain select count(id) from versions where project_id IN (80,115) AND project_id=115

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

2013-05-06 Thread Matt Clarkson
the distribution stats as the operation progresses and if it detects that it is changing the distribution of data beyond a certain threshold it would update the pg stats accordingly. -- Matt Clarkson Catalyst.Net Limited -- Sent via pgsql-performance mailing list (pgsql-performance

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

2013-05-07 Thread Matt Clarkson
On Tue, 2013-05-07 at 18:32 +1200, Mark Kirkwood wrote: On 07/05/13 18:10, Simon Riggs wrote: On 7 May 2013 01:23, mark.kirkw...@catalyst.net.nz wrote: I'm thinking that a variant of (2) might be simpler to inplement: (I think Matt C essentially beat me to this suggestion - he

[PERFORM] OFFSET/LIMIT - Disparate Performance w/ Go application

2014-06-12 Thread Matt Silverlock
Hi all. This might be tricky in so much as there’s a few moving parts (when isn’t there?), but I’ve tried to test the postgres side as much as possible. Trying to work out a potential database bottleneck with a HTTP application (written in Go): Pages that render HTML templates but don’t perform

Re: [PERFORM] OFFSET/LIMIT - Disparate Performance w/ Go application

2014-06-12 Thread Matt Silverlock
Thanks for the replies Jeff, Tom and Merlin. Pages that SELECT multiple rows with OFFSET and LIMIT conditions struggle to top 1.3k req/s Is that tested at the OFFSET and LIMIT of 0 and 15, as shown in the explain plan? Yes — 0 (OFFSET) and 16 (LIMIT), or 15 and 31 (i.e. “second page” of

Re: [PERFORM] 60 core performance with 9.3

2014-07-30 Thread Matt Clarkson
| 2.30 | 0.04 WALWriteLock | 3172725 | 457 | 24.67 | 0.08 CLogControlLock| 1012458 |6423 | 10.59 | 1.09 The same test done with a readonly workload show virtually no SpinDelay at all. Any thoughts or comments on these results are welcome! Regards, Matt

Re: [PERFORM] Storing Digital Video

2006-01-31 Thread Matt Davies | Postgresql List
Rodrigo Madera wrote: I am concerned with performance issues involving the storage of DV on a database. I though of some options, which would be the most advised for speed? 1) Pack N frames inside a container and store the container to the db. 2) Store each frame in a separate record in the

Re: [PERFORM] Loading the entire DB into RAM

2006-04-07 Thread Matt Davies | Postgresql List
If memory serves me correctly I have seen several posts about this in the past. I'll try to recall highlights. 1. Create a md in linux sufficiently large enough to handle the data set you are wanting to store. 2. Create a HD based copy somewhere as your permanent storage mechanism. 3. Start

<    1   2