Oracle does not make me happy. I am talking specifically about their 9i database. The database installer is slow and their empty databases are over a gigabyte in space. Doing a full database dump is simple but doing anything more complex is an enigma. Installing an Oracle client to access the database instead of just a driver is ridiculous. Oracle also lacks any sort of adequate graphical interface.
Most of all, I have never seen a product for the Enterprise that is so prone to failure and need to be recovered. Personally I choose to use SQL Server because everything is so much simpler. You have 1 data file and 1 transaction log (you can have more for more complex situations). In Oracle you have Rollback Segments, Control Files, Trace Files, Archive Logs and Database Files (which belong in table spaces which may be one or more files per tablespace).
You can argue that having all these seperate files provide a way to scale better. For example you could have one SAN dedicated to just one table space. However in practice, this is not the case. SQL 2005 is able to reach the same performance is Oracle with a much simpler architecture. Also My SQL is making huge in roads (although needs a lot more work to be as easy as SQL Server).
If you are running a Windows server then you can easily, and for free, use the free SQL Server called SQL Express (Previously called MSDE).
DISCLAIMER: Most of my posting here will be a lot easier to read than this one. I’ve had some major Oracle drama this past week. I will get off my soapbox and return to a better posting style after my Oracle drama has been concluded.