Re: [PERFORM] Poor performance for delete query

2014-04-25 Thread Tom Lane
Jonatan Evald Buus writes: > On 24 April 2014 23:25, Tom Lane wrote: >> Jonatan Evald Buus writes: >>> Why is "order2transaction_fk" being triggered twice? Is that because >>> there're two affected rows? >> No, I'd have expected a delete of multiple rows to show as calls=N, >> not N separate en

Re: [PERFORM] Server vacuuming the same table again and again

2014-04-25 Thread Дмитрий Шалашов
Turns out yesterday we fixed a bug and introduced a new bug, which was previously hidden by yet another bug which in turn we had fixed last week... %) In result last fix led to greatly increased number of requests to the database. But still, thanks for that, we found out about too frequent checkpo

Re: [PERFORM] Server vacuuming the same table again and again

2014-04-25 Thread Ilya Kosmodemiansky
Dmitry, On Fri, Apr 25, 2014 at 11:31 AM, Дмитрий Шалашов wrote: > Thanks, we'll try new autovacuum settings! I think things with vacuum will be much better. If not, try to find out if you have long running transaction (several minutes or more) and try to avoid such them. > > First, I have to

Re: [PERFORM] Server vacuuming the same table again and again

2014-04-25 Thread Torsten Förtsch
On 25/04/14 09:47, Дмитрий Шалашов wrote: > Half a day ago one of our production PG servers (arguably busiest one) > become very slow; I went to investigate the issue and found that it runs > simultaneously '(auto)VACUUM ANALYZE recommendations' - largest table on > that server - and checkpoint, gi

Re: [PERFORM] Server vacuuming the same table again and again

2014-04-25 Thread Дмитрий Шалашов
> How is you filesystem under database exactly mount? ext3 (rw) Thanks, we'll try new autovacuum settings! > That was happen after changing checkpoit_segments setting? First, I have to say that load comes and go in waves - we don't yet understood why. All new waves have that behaviour - free dis

Re: [PERFORM] Server vacuuming the same table again and again

2014-04-25 Thread Ilya Kosmodemiansky
On Fri, Apr 25, 2014 at 10:29 AM, Дмитрий Шалашов wrote: > Previously during load disk was 100% busy; now we have around 100 active > state queries, 100% loaded proc, but disk is virtually idle... That was happen after changing checkpoit_segments setting? > > > Best regards, > Dmitriy Shalashov

Re: [PERFORM] Server vacuuming the same table again and again

2014-04-25 Thread Ilya Kosmodemiansky
Dmitry, How is you filesystem under database exactly mount? (mount -l) And just in case, while increasing checkpoint_segments, better to increase checkpoint_timeout, otherwise all checkpoints will be still frequent because segment threshold will be never reached. You could monitor your pg_stat_bgw

Re: [PERFORM] pl/pgsql performance

2014-04-25 Thread Pavel Stehule
Hello 2014-04-25 10:48 GMT+02:00 Mehdi Ravanbakhsh : > Hi All > > I have one big Pl/Pgsql function (about 1500 line code) , i can divided > it to about 5 part and call each script from main script . In this case > i need to know which way is faster . > > and some question about pgsql : > >

[PERFORM] pl/pgsql performance

2014-04-25 Thread Mehdi Ravanbakhsh
Hi All I have one big Pl/Pgsql function (about 1500 line code) , i can divided it to about 5 part and call each script from main script . In this case i need to know which way is faster . and some question about pgsql : 1- is pgsql engine open one process for each script ? 2- how i can chos

Re: [PERFORM] Server vacuuming the same table again and again

2014-04-25 Thread Дмитрий Шалашов
And right now we have a new kind of problem. Previously during load disk was 100% busy; now we have around 100 active state queries, 100% loaded proc, but disk is virtually idle... Normally we have under 10 active queries. Any hints on that? Best regards, Dmitriy Shalashov 2014-04-25 12:22 GMT+

Re: [PERFORM] Server vacuuming the same table again and again

2014-04-25 Thread Дмитрий Шалашов
Hi Ilya! > Actually, thise two things are tightly bound and there is no chance to avoid vacuum, you can only postpone it, this kind of work eventually supposed to be done. I understand that autovacuum has to be done, but not right after previous autovacuum? And then again and again. And after can

Re: [PERFORM] Server vacuuming the same table again and again

2014-04-25 Thread Ilya Kosmodemiansky
Hi Dmitry, On Fri, Apr 25, 2014 at 9:47 AM, Дмитрий Шалашов wrote: > cancelled autovacuum and it seems to help. > In the morning autovacuum was back. And then it finished and I gone to work. Actually, thise two things are tightly bound and there is no chance to avoid vacuum, you can only postpo

[PERFORM] Server vacuuming the same table again and again

2014-04-25 Thread Дмитрий Шалашов
Hi! Half a day ago one of our production PG servers (arguably busiest one) become very slow; I went to investigate the issue and found that it runs simultaneously '(auto)VACUUM ANALYZE recommendations' - largest table on that server - and checkpoint, giving a 100% disk load, that resulted with que