So I'm reading Sun's _Configuring & Tuning Databases on the Solaris 
Platform_ book (ISBN: 0-13-083417-3). One of the first things mentioned 
in the book is that UFS is, well, slow. Especially because of how 
Solaris utilizes it. The authors contend that enabling directio(3C) can 
increase performance substantially. It can lead to problems with 
filesystems where strange things are done with files. Since databases 
tend to manage their files very well to begin with, the authors say 
this isn't normally a problem.

I searched the web for it, but all I found was some references to Zend. 
Additionally, I grepped through source only to realize that "direction" 
is used a lot. So I used the following find :

[goro:~/postgresql-7.3.1] alex% find . -type f -exec egrep -il 
'directio[^Nn]' {} \;

And also didn't find anything. The manpage for directio (Solaris 9) is 
here:

http://docs.sun.com/db/doc/816-0213/6m6ne37so?a=view

I haven't gotten my ultrasparc database server up yet, so I can't run 
any benchmarks against this. Is it possible somebody with some spare 
time could mount a filesystem with directio forced (forcedirectio) and 
run some benchmarks on a Solaris/UFS database?

Thanks
alex

--
alex avriette, unix geek for hire
http://envy.posixnap.net/
alex@posixnap.net


Thu, 20 Feb 2003 15:19:08 -0500
alex avriette <avriettea@speakeasy.net>
Postgres and 'directio' on Solaris/UFS