Re: [PERFORM] Abnormal performance difference between Postgres and MySQL

2009-02-26 Thread Claus Guttesen
The execution time has not improved. I am going to increase the shared_buffers now keeping the work_mem same. Have you performed a vacuum analyze? -- regards Claus When lenity and cruelty play for a kingdom, the gentler gamester is the soonest winner. Shakespeare -- Sent via

Re: [PERFORM] Abnormal performance difference between Postgres and MySQL

2009-02-26 Thread Akos Gabriel
Thu, 26 Feb 2009 09:00:07 +0100 -n Claus Guttesen kome...@gmail.com írta: The execution time has not improved. I am going to increase the shared_buffers now keeping the work_mem same. Have you performed a vacuum analyze? and reindex -- Üdvözlettel, Gábriel Ákos -=E-Mail

Re: [PERFORM] Abnormal performance difference between Postgres and MySQL

2009-02-26 Thread Farhan Husain
On Wed, Feb 25, 2009 at 4:10 PM, Kevin Grittner kevin.gritt...@wicourts.gov wrote: Farhan Husain russ...@gmail.com wrote: The machine postgres is running on has 4 GB of RAM. In addition to the other suggestions, you should be sure that effective_cache_size is set to a reasonable value,

Re: [PERFORM] Abnormal performance difference between Postgres and MySQL

2009-02-26 Thread Farhan Husain
On Wed, Feb 25, 2009 at 6:07 PM, Scott Carey sc...@richrelevance.comwrote: I will second Kevin’s suggestion. Unless you think you will have more than a few dozen concurrent queries, start with work_mem around 32MB. For the query here, a very large work_mem might help it hash join depending

Re: [PERFORM] Abnormal performance difference between Postgres and MySQL

2009-02-26 Thread Kevin Grittner
Farhan Husain russ...@gmail.com wrote: Thanks a lot Scott! I think that was the problem. I just changed the default statistics target to 50 and ran explain. The plan changed and I ran explain analyze. Now it takes a fraction of a second! Yeah, the default of 10 has been too low. In 8.4 it

Re: [PERFORM] Abnormal performance difference between Postgres and MySQL

2009-02-26 Thread Scott Marlowe
On Thu, Feb 26, 2009 at 12:10 PM, Steve Clark scl...@netwolves.com wrote: Can this be set in the postgresql.conf file? default_statistics_target = 50 Yep. It will take affect after a reload and after the current connection has been reset. If you want to you also set a default for a database

Re: [PERFORM] Abnormal performance difference between Postgres and MySQL

2009-02-26 Thread Steve Clark
Kevin Grittner wrote: Farhan Husain russ...@gmail.com wrote: Thanks a lot Scott! I think that was the problem. I just changed the default statistics target to 50 and ran explain. The plan changed and I ran explain analyze. Now it takes a fraction of a second! Yeah, the default of 10 has been