<flame bait>
PostgreSQL is the Mach of the database world.
It has lots of cool sophisticated stuff, but if you attempt to
use it seriously, you discover it isn't sufficiently reliable
and rounded out for production use, instead it appears the result
of a whole bunch of graduate students hacking on it in different
random ways to get PhDs. Nodays though some real programmers have
picked it up, and are turning it into something useful.
Hmmm. Perhaps that is a little unfair. After all, it never got
hyped the same was as Mach was hyped by the academic community.
</flame bait>
Having used and seen PostgreSQL used a fair amount within Cygnus,
I think we would have been better going straight to Oracle. It
is fine for hacking, but I'd avoid it if I was trying to run a
serious business.
PostgreSQL is a serious database, with a lot of cool features.
Unfortunately it isn't sufficiently reliable for a real database.
It seems to crash once every 2-3 months. Also various features
are missing. Eg. there might be a date type, but they forgot to
provide the min operator for dates, or there is no way to check
if a date lies in a particular date range type. It also doesn't
allow you to specify constraints on data fields, and either doesn't
have, or recommends avoiding because they are unreliable, trigger
conditions that cause a statement to execute when a particular
event occurs.
mySQL? I assume this is a new name for mSQL. All I remeber is
it isn't free, and while fairly good for use with Perl, doesn't
approach the serious database status of PostgreSQL.
Havn't played with GNU SQL. Alas.