I'd like to store using XML in a separate text file for each record created because it's easy and gives me flexibility. I can add data fields without tweaking tables in a MySQL database. I can add users easily and keep their data in a separate directory that is easy to locate. I'm told that storing/retrieving data in text files is slow and so is parsing that data. I've never used XML::Parser but I thought I'd give it a spin.
I hear MySQL is speedy, but it seems to me that it adds complexity to such a degree that it may not be an even trade off. I could store data in an XML format in a single field in a MySQL database, but I'd still have to parse it.
In my experience you'll be just fine using XML with that amount of data, but I would try to come up with some simple tests searching through sample data to see if it really meets your performance needs. On the other hand, I'd still consider using MySQL - it's really not that complex, and you gain a lot of flexibility. By that I mean once everything is in a group of tables, you can then do lots of ad-hoc queries on it to find out useful information, in a much easier way than writing a perl script every time you want to know something. If you can handle perl programming, you'll probably be able to learn enough about MySQL and the perl DBI interface to be doing useful stuff in less than a day. There are a ton of tutorials out there and the MySQL manual is excellent.
Ian
