[PERFORM] Effects of setting linux block device readahead size

Hi all, I've started to display the effects of changing the Linux block device readahead buffer to the sequential read performance using fio. There are lots of raw data buried in the page, but this is what I've distilled thus far. Please have a look and let me know what you think: http://wiki.p

Re: [PERFORM] too many clog files

Alvaro Herrera wrote: > Move the old clog files back where they were, and run VACUUM FREEZE in > all your databases. That should clean up all the old pg_clog files, if > you're really that desperate. Has anyone actually seen a CLOG file get removed under 8.2 or 8.3? How about 8.1? I'm probably

Re: [PERFORM] How to measure IO performance?

On Tue, Sep 9, 2008 at 7:59 AM, Andre Brandt <[EMAIL PROTECTED]> wrote: > Hi out there, > > I've some little questions, perhaps you can help me... > > So in order to get rid of wait I/O (as far as possible), we have to > increase the I/O performance. Because of there are a lot storage systems > out

[PERFORM] How to measure IO performance?

Hi out there, I've some little questions, perhaps you can help me... At the moment, we're planning our new clustered ERP system which consists of a java application server and a postgresql database. The hardware, which is actually used for that system isn't able to handle the workload (2 Processo

Re: [PERFORM] too many clog files

Hi Duan, As others have said, you should probably attempt to run pg_dump to export your database. If that doesn't work, consider restoring from backup. If the dump does work, you can create a clean PGDATA directory (using initdb like when you setup your original installation), and create a fr