Re: The old raw devices chestnut.

"Jim Smith" <jim@jimsmith.demon.co.uk> wrote in message news:dS4PuczgskeAFwJq@jimsmith.demon.co.uk... > Note the cross-posting - but no flame wars please. > > This question was prompted by a thread on the a postgres mailing list > during which someone (Gregory Williamson) claimed > > <quote> > raw devices, at least on Solaris, are about 10 times as fast as cooked > file systems for Informix. > <quote> I have 3 thoughts on this. 1. A FS is an extra layer of code between the db and the hardware, to that extent if you are comparing a direct read from the actual disk - rather than a read from a cache somewhere - then RAW will be faster - ten times seems a hefty claim though. 2. Who cares - what matters isn't the speed of the disk read, but the response time for the end users screens/jobs - if and only iff you can show that this is slow and the speed is caused by a file system would you consider RAW. 3. show us the numbers and the experiment done to prove the statement. -- Niall Litchfield Oracle DBA Audit Commission UK http://www.niall.litchfield.dial.pipex.com ***************************************** Please include version and platform and SQL where applicable It makes life easier and increases the likelihood of a good answer ******************************************