Postgresql vs. Mysql

Hi All,

I'm sure that this question gets asked a lot.  Can someone reference me to good material on why one would choose one
vs.another?  I greatly appreciate it! 

I am designing a database (first ever, after reading a couple of texts) for a company department that currently doesn't
haveone.  I'm pretty comfortable with the correctness of the structure and have a script ready to build the database
withSQL 
commands.  The table structure is such that it appears that many queries would be calling other sub-queries
(functions?). Other than that, there is nothing special about the database.  I plan to use php to interface the
databaseserver with the internal 
web and will run it on an HPUX environment machine with an Apache web server.

Thanks for the help.

Tom