[PERFORM] Poor performance after update from SLES11 SP1 to SP2

2013-02-21 Thread Mark Smith
Hardware: IBM X3650 M3 (2 x Xeon X5680 6C 3.33GHz), 96GB RAM. IBM X3524 with RAID 10 ext4 (noatime,nodiratime,data=writeback,barrier=0) volumes for pg_xlog / data / indexes. Software: SLES 11 SP2 3.0.58-0.6.2-default x86_64, PostgreSQL 9.0.4. max_connections = 1500 shared_buffers = 16GB work_mem

Re: [PERFORM] Poor performance after update from SLES11 SP1 to SP2

2013-02-21 Thread Vasilis Ventirozos
Hello Mark, if i was you i would start with making basic benchmarks regarding IO performance (bonnie++ maybe?) and i would check my sysctl.conf. your parameters look ok to me. when these delays occur have you noticed whats causing it ? An output of vmstat when the delays are happening would also

Re: [PERFORM] Poor performance after update from SLES11 SP1 to SP2

2013-02-21 Thread Scott Marlowe
There's another thread in the list started by Josh Berkus about poor performance with a similar kernel. I'd look that thread up and see if you and he have enough in common to work together on this. On Thu, Feb 21, 2013 at 2:59 AM, Mark Smith smithmark...@gmail.com wrote: Hardware: IBM X3650 M3

Re: [PERFORM] Poor performance after update from SLES11 SP1 to SP2

2013-02-21 Thread Sergey Konoplev
On Thu, Feb 21, 2013 at 1:59 AM, Mark Smith smithmark...@gmail.com wrote: Software: SLES 11 SP2 3.0.58-0.6.2-default x86_64, PostgreSQL 9.0.4. [skipped] Problem: We have been running PostgreSQL 9.0.4 on SLES11 SP1, last kernel in use was 2.6.32-43-0.4, performance has always been great. Since

[PERFORM] Are bitmap index scans slow to start?

2013-02-21 Thread Carlo Stonebanks
(Sorry moderators for any double posts, I keep making subscription errors. Hopefully this one gets through) Hi speed freaks, Can anyone tell me why the bitmap heap scan takes so long to start for this query? (SQL and EXPLAIN ANALYZE follows). The big culprit in this appears to be: - Bitmap

Re: [PERFORM] Are bitmap index scans slow to start?

2013-02-21 Thread Jeff Janes
On Thu, Feb 21, 2013 at 8:57 AM, Carlo Stonebanks stonec.regis...@sympatico.ca wrote: (Sorry moderators for any double posts, I keep making subscription errors. Hopefully this one gets through) Hi speed freaks, Can anyone tell me why the bitmap heap scan takes so long to start for this