Noob Centos Admin wrote:
Hi,
If you want a fast database forget about file system caching, use Direct I/O and put your memory to better use - application level caching.
The web application is written in PHP and runs off MySQL and/or Postgresql. So I don't think I can access the raw disk data directly, nor do I think it would be safe since that bypasses the DBMS's checks.
Which is it? mysql or postgresql or both? Have you actually determined that i/o is in fact the bottleneck?
Is the webapp maintaining persistent connections to mysql or is it continually connecting and disconnecting? mysql sucks big time if you have a good few hundred connections being setup and torn down all the time.
Are complicated relationships being stored in postgresql and not in mysql? I do not know how things are now but mysql has a history of only being good for simple selects.