Re: [PERFORM] Very poor read performance, query independent

2017-07-18 Thread Charles Nadeau
Claudio, Find attached the iostat measured while redoing the query above (iostat1.txt). sda holds my temp directory (noop i/o scheduler), sdb the swap partition (cfq i/o scheduler) only and sdc (5 disks RAID0, noop i/o scheduler) holds the data. I didn't pay attention to the load caused by 12 para

Re: [PERFORM] Very poor read performance, query independent

2017-07-18 Thread Claudio Freire
On Tue, Jul 18, 2017 at 6:20 AM, Charles Nadeau wrote: > Claudio, > > At one moment > during the query, there is a write storm to the swap drive (a bit like this > case: > https://www.postgresql.org/message-id/AANLkTi%3Diw4fC2RgTxhw0aGpyXANhOT%3DXBnjLU1_v6PdA%40mail.gmail.com). > I can hardly expl

Re: [PERFORM] Very poor read performance, query independent

2017-07-18 Thread Claudio Freire
On Tue, Jul 18, 2017 at 1:01 PM, Claudio Freire wrote: > On Tue, Jul 18, 2017 at 6:20 AM, Charles Nadeau > wrote: >> Claudio, >> >> At one moment >> during the query, there is a write storm to the swap drive (a bit like this >> case: >> https://www.postgresql.org/message-id/AANLkTi%3Diw4fC2RgTxhw

Re: [PERFORM] Very poor read performance, query independent

2017-07-18 Thread Justin Pryzby
On Tue, Jul 18, 2017 at 02:13:58PM -0300, Claudio Freire wrote: > On Tue, Jul 18, 2017 at 1:01 PM, Claudio Freire > wrote: > > On Tue, Jul 18, 2017 at 6:20 AM, Charles Nadeau > > wrote: > >> Claudio, > >> > >> At one moment > >> during the query, there is a write storm to the swap drive (a bit l

Re: [PERFORM] Very poor read performance, query independent

2017-07-18 Thread Scott Marlowe
On Tue, Jul 18, 2017 at 3:20 AM, Charles Nadeau wrote: > Claudio, > > Find attached the iostat measured while redoing the query above > (iostat1.txt). sda holds my temp directory (noop i/o scheduler), sdb the > swap partition (cfq i/o scheduler) only and sdc (5 disks RAID0, noop i/o > scheduler) h

[PERFORM] Performance degradation from PostgreSQL 8.2.21 to PostgreSQL 9.3.2

2017-07-18 Thread fx TATEISHI KOJI
Issuing exactly the same query as PostgreSQL 8.2.21 and PostgreSQL 9.3.2 will slow the response by 6.4 ms on average. What could be the cause? Measurement method is as follows. ・ PostgreSQL 8.2.21 installation ★Measurement ・ Export DUMP of PostgreSQL 8.2.21 ・ PostgreSQL 8.2.21 uninstallation ・ Po

[PERFORM] Re: Performance degradation from PostgreSQL 8.2.21 to PostgreSQL 9.3.2

2017-07-18 Thread Albe Laurenz
fx TATEISHI KOJI wrote: > Issuing exactly the same query as PostgreSQL 8.2.21 and PostgreSQL 9.3.2 will > slow the > response by 6.4 ms on average. > What could be the cause? > Measurement method is as follows. > ・ PostgreSQL 8.2.21 installation > ★Measurement > ・ Export DUMP of PostgreSQL 8.2.21