Re: [PERFORM] 8.1 -> 8.4 regression

2010-02-16 Thread Tom Lane
Ben Chobot writes: > Awesome, that did the trick. Thanks Tom! So I understand better, why is my > case not the normal, better case? Well, the short answer is that the 8.4 changes here are in the nature of two steps forward and one step back. The long-term goal is to increase the planner's abili

Re: [PERFORM] another 8.1->8.4 regression

2010-02-16 Thread Ben Chobot
On Feb 16, 2010, at 1:29 PM, Ben Chobot wrote: > I'm having problems with another one of my queries after moving from 8.1.19 > to 8.4.2. On 8.1.19, the plan looked like this: > > http://wood.silentmedia.com/bench/8119 > > That runs pretty well. On 8.4.2, the same query looks like this: > > htt

Re: [PERFORM] Linux I/O tuning: CFQ vs. deadline

2010-02-16 Thread Jeff Davis
On Mon, 2010-02-08 at 09:49 -0800, Josh Berkus wrote: > FWIW, back when deadline was first introduced Mark Wong did some tests > and found Deadline to be the fastest of 4 on DBT2 ... but only by about > 5%. If the read vs. checkpoint analysis is correct, what was happening > is the penalty for che

[PERFORM] another 8.1->8.4 regression

2010-02-16 Thread Ben Chobot
I'm having problems with another one of my queries after moving from 8.1.19 to 8.4.2. On 8.1.19, the plan looked like this: http://wood.silentmedia.com/bench/8119 That runs pretty well. On 8.4.2, the same query looks like this: http://wood.silentmedia.com/bench/842_bad If I turn off mergejoin

Re: [PERFORM] Almost infinite query -> Different Query Plan when changing where clause value

2010-02-16 Thread lionel duboeuf
lionel duboeuf a écrit : Thank you Kevin and Scott for all the explanations. ;-) regards Lionel Sorry for forgetting Jorge also. regards. All this ,encourage me to know more about database management. -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make

Re: [PERFORM] Almost infinite query -> Different Query Plan when changing where clause value

2010-02-16 Thread lionel duboeuf
Thank you Kevin and Scott for all the explanations. ;-) regards Lionel -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance

Re: [PERFORM] Why index is not using here?

2010-02-16 Thread Kevin Grittner
AI Rumman wrote: > Merge Left Join (cost=0.00..1383629.28 rows=231572 width=264) > (actual time=0.166..1924.417 rows=231572 loops=1) >Merge Cond: ("outer".parentid = "inner".accountid) >-> Index Scan using vtiger_account_parentid_idx on > vtiger_account (cost=0.00..642475.34 rows=2315

Re: [PERFORM] Dell PERC H700/H800

2010-02-16 Thread Bruce Momjian
Greg Smith wrote: > I've been full-on vocally anti-Dell ever since they started releasing > PCs with the non-standard ATX power supply pinout; that was my final > straw with their terrible quality decisions. Yep, makes me feel validated for all of the anti-Dell advice I have given over the years

Re: [PERFORM] Almost infinite query -> Different Query Plan when changing where clause value

2010-02-16 Thread Kevin Grittner
lionel duboeuf wrote: > I stopped postgresql > I started postgresql (and as default autovacuum daemon) > I restored the databases (need to restore 4 databases) > It seems that after database 1 have been restored, autovacumm > started on it and has been stopped while restoring database 2. > Doe

Re: [PERFORM] Why index is not using here?

2010-02-16 Thread AI Rumman
A mistake on the previous mail. explain analyze select * from vtiger_account LEFT JOIN vtiger_account vtiger_account2 ON vtiger_account.parentid = vtiger_account2.accountid QUERY PLAN --

[PERFORM] Why index is not using here?

2010-02-16 Thread AI Rumman
I am getting seq_scan on vtiger_account. Index is not using. Could anyone please tell me what the reason is? explain analyze select * from vtiger_account LEFT JOIN vtiger_account vtiger_account2 ON vtiger_account.parentid = vtiger_account2.accountid

Re: [PERFORM] Almost infinite query -> Different Query Plan when changing where clause value

2010-02-16 Thread lionel duboeuf
Here is my log analysis: Due to a database recovery task it appears that: I stopped postgresql I started postgresql (and as default autovacuum daemon) I restored the databases (need to restore 4 databases) It seems that after database 1 have been restored, autovacumm started on it an

Re: [PERFORM] Almost infinite query -> Different Query Plan when changing where clause value

2010-02-16 Thread lionel duboeuf
Here is my log analysis: Due to a database recovery task it appears that: I stopped postgresql I started postgresql (and as default autovacuum daemon) I restored the databases (need to restore 4 databases) It seems that after database 1 have been restored, autovacumm started on it an