Re: [PERFORM] Dell PERC H700/H800

Matthew Wakeling wrote: Just a heads up - apparently the more recent Dell RAID controllers will no longer recognise hard discs that weren't sold through Dell. http://www.channelregister.co.uk/2010/02/10/dell_perc_11th_gen_qualified_hdds_only/ As one of the comments points out, that kind o

Re: [PERFORM] Dell PERC H700/H800

On Thu, Feb 11, 2010 at 1:11 PM, James Mansion wrote: > Matthew Wakeling wrote: >> >> Just a heads up - apparently the more recent Dell RAID controllers will no >> longer recognise hard discs that weren't sold through Dell. >> >> >> http://www.channelregister.co.uk/2010/02/10/dell_perc_11th_gen_qu

Re: [PERFORM] Dell PERC H700/H800

2010/2/11 James Mansion : > Matthew Wakeling wrote: >> >> Just a heads up - apparently the more recent Dell RAID controllers will no >> longer recognise hard discs that weren't sold through Dell. >> >> >> http://www.channelregister.co.uk/2010/02/10/dell_perc_11th_gen_qualified_hdds_only/ >> >> As o

Re: [PERFORM] moving pg_xlog -- yeah, it's worth it!

Aidan Van Dyk wrote: > Alvaro Herrera wrote: >> Hmm, so maybe the performance benefit is not from it being on a >> separate array, but from it being RAID1 instead of RAID5? > > Or the cumulative effects of: > 1) Dedicated spindles/Raid1 > 2) More BBU cache available (I can't imagine the OS pair

Re: [PERFORM] moving pg_xlog -- yeah, it's worth it!

* Alvaro Herrera [100211 12:58]: > Hmm, so maybe the performance benefit is not from it being on a separate > array, but from it being RAID1 instead of RAID5? Or the cumulative effects of: 1) Dedicated spindles/Raid1 2) More BBU cache available (I can't imagine the OS pair writing much) 3) not be

Re: [PERFORM] moving pg_xlog -- yeah, it's worth it!

Kevin Grittner wrote: > Another example of why I shouldn't trust my memory. Per the > hardware tech: > > > OS: /dev/sda is RAID1 - 2 x 2.5" 15k SAS disk > pg_xlog: /dev/sdb is RAID1 - 2 x 2.5" 15k SAS disk > > These reside on a ServeRAID-MR10k controller with 256MB BB cache

Re: [PERFORM] moving pg_xlog -- yeah, it's worth it!

"Kevin Grittner" wrote: > Jesper Krogh wrote: > >> Sorry if it is obvious.. but what filesystem/OS are you using and >> do you have BBU-writeback on the main data catalog also? > File system is xfs noatime,nobarrier for all data; OS is on ext3. > I *think* the pg_xlog mirrored pair is hangin

Re: [PERFORM] Dell PERC H700/H800

On Thu, Feb 11, 2010 at 5:39 AM, Matthew Wakeling wrote: > > Just a heads up - apparently the more recent Dell RAID controllers will no > longer recognise hard discs that weren't sold through Dell. > > http://www.channelregister.co.uk/2010/02/10/dell_perc_11th_gen_qualified_hdds_only/ > > As one o

Re: [PERFORM] Dell PERC H700/H800

On Thu, 2010-02-11 at 12:39 +, Matthew Wakeling wrote: > Just a heads up - apparently the more recent Dell RAID controllers will no > longer recognise hard discs that weren't sold through Dell. > > http://www.channelregister.co.uk/2010/02/10/dell_perc_11th_gen_qualified_hdds_only/ > > As one

Re: [PERFORM] moving pg_xlog -- yeah, it's worth it!

On Thu, Feb 11, 2010 at 4:29 AM, Bruce Momjian wrote: > Kevin Grittner wrote: >> Jesper Krogh wrote: >> >> > Sorry if it is obvious.. but what filesystem/OS are you using and >> > do you have BBU-writeback on the main data catalog also? >> >> Sorry for not providing more context. >> >> ATHENA:/va

Re: [PERFORM] perf problem with huge table

Dave Crooke wrote: > On Wed, Feb 10, 2010 at 5:30 PM, Jon Lewison > wrote: > > > > Just a nit, but Oracle implements MVCC. 90% of the databases out > there do. > > > Sorry, I spoke imprecisely. What I meant was the difference in how the > rows are stored i

Re: [PERFORM] Re: 512,600ms query becomes 7500ms... but why? Postgres 8.3 query planner quirk?

On Wed, Feb 10, 2010 at 8:52 PM, Bryce Nesbitt wrote: > If you guys succeed in making this class of query perform, you'll have beat > out the professional consulting firm we hired, which was all but useless! > The query is usually slow, but particular combinations of words seem to make > it obscen

[PERFORM] Dell PERC H700/H800

Just a heads up - apparently the more recent Dell RAID controllers will no longer recognise hard discs that weren't sold through Dell. http://www.channelregister.co.uk/2010/02/10/dell_perc_11th_gen_qualified_hdds_only/ As one of the comments points out, that kind of makes them no longer SATA

Re: [PERFORM] moving pg_xlog -- yeah, it's worth it!

Kevin Grittner wrote: > Jesper Krogh wrote: > > > Sorry if it is obvious.. but what filesystem/OS are you using and > > do you have BBU-writeback on the main data catalog also? > > Sorry for not providing more context. > > ATHENA:/var/pgsql/data # uname -a > Linux ATHENA 2.6.16.60-0.39.3-smp

Re: [PERFORM] perf problem with huge table

> Hi all, > > i am trying to move my app from M$sql to PGsql, but i need a bit of help > :) Except from all the other good advises about partitioning the dataset and such there is another aspect to "keep in mind". When you have a large dataset and your queries become "IO-bound" the "tuple density"