Re: [PERFORM] strange performance regression between 7.4 and 8.1

2007-03-02 Thread Florian Weimer
* Alex Deucher: I have noticed a strange performance regression and I'm at a loss as to what's happening. We have a fairly large database (~16 GB). Sorry for asking, but is this a typo? Do you mean 16 *TB* instead of 16 *GB*? If it's really 16 GB, you should check if it's cheaper to buy

Re: [PERFORM] Improving query performance

2007-03-02 Thread David Leangen
And this is the actual query: I think you need to look into full-text indexing (see tsearch2). Thanks, Tom. Yes, we know this. This is just a temporary fix that we needed to get up today for biz reasons. Implementing full-text searching within a few short hours was out of the question.

Re: [PERFORM] stats collector process high CPU utilization

2007-03-02 Thread Magnus Hagander
Tom Lane wrote: Merlin Moncure [EMAIL PROTECTED] writes: On 3/2/07, Tom Lane [EMAIL PROTECTED] wrote: Merlin Moncure [EMAIL PROTECTED] writes: I think this explains the trigger that was blowing up my FC4 box. I dug in the archives a bit and couldn't find the report you're referring to? I

Re: [PERFORM] strange performance regression between 7.4 and 8.1

2007-03-02 Thread Carlos Moreno
Florian Weimer wrote: * Alex Deucher: I have noticed a strange performance regression and I'm at a loss as to what's happening. We have a fairly large database (~16 GB). Sorry for asking, but is this a typo? Do you mean 16 *TB* instead of 16 *GB*? If it's really 16 GB, you should

Re: [PERFORM] [EMAIL PROTECTED]: Progress on scaling of FreeBSD on 8 CPU systems]

2007-03-02 Thread Alvaro Herrera
From: Kris Kennaway [EMAIL PROTECTED] We have recently made significant progress on optimizing for MySQL running on an 8-core amd64 system. The graph of results may be found here: http://www.freebsd.org/~kris/scaling/scaling.png This shows the graph of MySQL transactions/second

Re: [PERFORM] strange performance regression between 7.4 and 8.1

2007-03-02 Thread Alex Deucher
On 3/2/07, Florian Weimer [EMAIL PROTECTED] wrote: * Alex Deucher: I have noticed a strange performance regression and I'm at a loss as to what's happening. We have a fairly large database (~16 GB). Sorry for asking, but is this a typo? Do you mean 16 *TB* instead of 16 *GB*? If it's

Re: [PERFORM] strange performance regression between 7.4 and 8.1

2007-03-02 Thread Ron
At 08:56 AM 3/2/2007, Carlos Moreno wrote: Florian Weimer wrote: * Alex Deucher: I have noticed a strange performance regression and I'm at a loss as to what's happening. We have a fairly large database (~16 GB). Sorry for asking, but is this a typo? Do you mean 16 *TB* instead of 16

Re: [PERFORM] strange performance regression between 7.4 and 8.1

2007-03-02 Thread Alex Deucher
On 3/1/07, Jeff Frost [EMAIL PROTECTED] wrote: On Thu, 1 Mar 2007, Alex Deucher wrote: here are some examples. Analyze is still running on the new db, I'll post results when that is done. Mostly what our apps do is prepared row selects from different tables: select c1,c2,c3,c4,c5 from t1

Re: [PERFORM] strange performance regression between 7.4 and 8.1

2007-03-02 Thread Ron
At 10:16 AM 3/2/2007, Alex Deucher wrote: On 3/2/07, Florian Weimer [EMAIL PROTECTED] wrote: * Alex Deucher: I have noticed a strange performance regression and I'm at a loss as to what's happening. We have a fairly large database (~16 GB). Sorry for asking, but is this a typo? Do you

Re: [PERFORM] [EMAIL PROTECTED]: Progress on scaling of FreeBSD on 8 CPU systems]

2007-03-02 Thread Arjen van der Meijden
Alvaro Herrera wrote: Interesting -- the MySQL/Linux graph is very similar to the graphs from the .nl magazine posted last year. I think this suggests that the MySQL deficiency was rather a performance bug in Linux, not in MySQL itself ... The latest benchmark we did was both with Solaris and

Re: [PERFORM] strange performance regression between 7.4 and 8.1

2007-03-02 Thread Alex Deucher
On 3/2/07, Ron [EMAIL PROTECTED] wrote: At 10:16 AM 3/2/2007, Alex Deucher wrote: On 3/2/07, Florian Weimer [EMAIL PROTECTED] wrote: * Alex Deucher: I have noticed a strange performance regression and I'm at a loss as to what's happening. We have a fairly large database (~16 GB). Sorry

Re: [PERFORM] strange performance regression between 7.4 and 8.1

2007-03-02 Thread Tom Lane
Alex Deucher [EMAIL PROTECTED] writes: Anyway, new numbers after the analyze. Unfortunately, they are improved, but still not great: Why are the index names different between the old and new servers? Is that just cosmetic, or is 8.2 actually picking a different (and less suitable) index for the

Re: [PERFORM] strange performance regression between 7.4 and 8.1

2007-03-02 Thread Alex Deucher
On 3/2/07, Tom Lane [EMAIL PROTECTED] wrote: Alex Deucher [EMAIL PROTECTED] writes: Anyway, new numbers after the analyze. Unfortunately, they are improved, but still not great: Why are the index names different between the old and new servers? Is that just cosmetic, or is 8.2 actually

Re: [PERFORM] [EMAIL PROTECTED]: Progress on scaling of FreeBSD on 8 CPU systems]

2007-03-02 Thread Scott Marlowe
On Fri, 2007-03-02 at 09:01, Alvaro Herrera wrote: From: Kris Kennaway [EMAIL PROTECTED] We have recently made significant progress on optimizing for MySQL running on an 8-core amd64 system. The graph of results may be found here: http://www.freebsd.org/~kris/scaling/scaling.png

Re: [PERFORM] strange performance regression between 7.4 and 8.1

2007-03-02 Thread Scott Marlowe
On Fri, 2007-03-02 at 10:03, Alex Deucher wrote: On 3/2/07, Ron [EMAIL PROTECTED] wrote: At 10:16 AM 3/2/2007, Alex Deucher wrote: d= you went from local HD IO to a SAN (many differences hidden in that one line... ...and is the physical layout of tables and things like pg_xlog sane on

Re: [PERFORM] strange performance regression between 7.4 and 8.1

2007-03-02 Thread Ron
At 11:03 AM 3/2/2007, Alex Deucher wrote: On 3/2/07, Ron [EMAIL PROTECTED] wrote: May I suggest that it is possible that your schema, queries, etc were all optimized for pg 7.x running on the old HW? (explain analyze shows the old system taking ~1/10 the time per row as well as estimating the

Re: [PERFORM] strange performance regression between 7.4 and 8.1

2007-03-02 Thread Anton Rommerskirchen
Am Donnerstag 01 März 2007 21:44 schrieb Alex Deucher: Hello, I have noticed a strange performance regression and I'm at a loss as to what's happening. We have a fairly large database (~16 GB). The original postgres 7.4 was running on a sun v880 with 4 CPUs and 8 GB of ram running Solaris

Re: [PERFORM] strange performance regression between 7.4 and 8.1

2007-03-02 Thread Alvaro Herrera
Florian Weimer escribió: Locale settings make a huge difference for sorting and LIKE queries. We usually use the C locale and SQL_ASCII encoding, mostly for performance reasons. (Proper UTF-8 can be enforced through constraints if necessary.) Hmm, you are aware of varchar_pattern_ops and

Re: [PERFORM] strange performance regression between 7.4 and 8.1

2007-03-02 Thread Alex Deucher
On 3/2/07, Ron [EMAIL PROTECTED] wrote: At 11:03 AM 3/2/2007, Alex Deucher wrote: On 3/2/07, Ron [EMAIL PROTECTED] wrote: May I suggest that it is possible that your schema, queries, etc were all optimized for pg 7.x running on the old HW? (explain analyze shows the old system taking ~1/10 the

Re: [PERFORM] Array indexes, GIN?

2007-03-02 Thread Jeff Davis
On Thu, 2007-03-01 at 19:59 -0800, Adam L Beberg wrote: On the surface, looks like a job for GIN, but GIN seems undocumented, specifically mentions it doesn't support the deletes we'll have many of since it's designed for word searching apparently, the performance It can delete an entry for

Re: [PERFORM] strange performance regression between 7.4 and 8.1

2007-03-02 Thread Ron
At 02:43 PM 3/2/2007, Alex Deucher wrote: On 3/2/07, Ron [EMAIL PROTECTED] wrote: ...and I still think looking closely at the actual physical layout of the tables in the SAN is likely to be worth it. How would I go about doing that? Alex Hard for me to give specific advice when I don't

Re: [PERFORM] strange performance regression between 7.4 and 8.1

2007-03-02 Thread Alex Deucher
On 3/2/07, Ron [EMAIL PROTECTED] wrote: At 02:43 PM 3/2/2007, Alex Deucher wrote: On 3/2/07, Ron [EMAIL PROTECTED] wrote: ...and I still think looking closely at the actual physical layout of the tables in the SAN is likely to be worth it. How would I go about doing that? Alex Hard for me to

Re: [PERFORM] strange performance regression between 7.4 and 8.1

2007-03-02 Thread Guido Neitzer
On 02.03.2007, at 14:20, Alex Deucher wrote: Ah OK. I see what you are saying; thank you for clarifying. Yes, the SAN is configured for maximum capacity; it has large RAID 5 groups. As I said earlier, we never intended to run a DB on the SAN, it just happened to come up, hence the

Re: [PERFORM] strange performance regression between 7.4 and 8.1

2007-03-02 Thread Jeff Frost
On Fri, 2 Mar 2007, Guido Neitzer wrote: On 02.03.2007, at 14:20, Alex Deucher wrote: Ah OK. I see what you are saying; thank you for clarifying. Yes, the SAN is configured for maximum capacity; it has large RAID 5 groups. As I said earlier, we never intended to run a DB on the SAN, it

Re: [PERFORM] stats collector process high CPU utilization

2007-03-02 Thread Bruce Momjian
Sorry, I introduced this bug. --- Tom Lane wrote: Benjamin Minshall [EMAIL PROTECTED] writes: Tom Lane wrote: It's sounding like what you had was just transient bloat, in which case it might be useful to inquire

Re: [PERFORM] strange performance regression between 7.4 and 8.1

2007-03-02 Thread Alex Deucher
On 3/2/07, Jeff Frost [EMAIL PROTECTED] wrote: On Fri, 2 Mar 2007, Guido Neitzer wrote: On 02.03.2007, at 14:20, Alex Deucher wrote: Ah OK. I see what you are saying; thank you for clarifying. Yes, the SAN is configured for maximum capacity; it has large RAID 5 groups. As I said

Re: [PERFORM] Upgraded to 8.2.3 --- still having performance issues

2007-03-02 Thread Dennis Bjorklund
Carlos Moreno skrev: The system does very frequent insertions and updates --- the longest table has, perhaps, some 20 million rows, and it's indexed (the primary key is the combination of two integer fields). This longest table only has inserts (and much less frequent selects), at a peak rate