Re: ext3 filesystem / linux 7.3

Chris,

> ...there is waaay too much hearsay going on in this thread.  Let's come
> up with an acceptable test battery and actually settle it once and for
> all with good hard numbers.  It would be worth my while to spend some
> time on this since the developers I support currently hate pgsql due to
> performance complaints (on servers that predate my employment there).
> So if I am going to move them to better servers it would be worth my
> while to do some homework on what OS and FS is best.

You're not going to be able to determine this for certain, but at least you
should be able to debunk some myths.  Here's my suggested tests:

1) Read-only test -- numerous small rapidfire queries in the fashion of a PHP
web application.  PGBench already does this one test ok, maybe you could use
that.

2) Complex query test -- run a few 12-table queries with CASE statements,
custom functions and subselects and/or UNIONs.

3) Transaction Test -- hit the database with numerous rapid-fire single row
updates to a few tables.

4) OLAP Test -- do a few massive updates to thousands of rows based on related
data and/or cascading updates to multiple tables and dozens-hundreds of rows.
Create large temp tables based on Joe Conway's Crosstab.

5) Mixed use test: combine 1, 2, & 3 in a ratio of 70% 10% 20% on several
simultaneous connections.

Of course this requires us to have a sample database with at least 100,000
rows of data in one or two tables plus at least 5-10 additional tables with
realistically complex relationships.  Donor, anyone?

Also, we'll have to talk about .conf files ...

--
-Josh Berkus
 Aglio Database Solutions
 San Francisco