I have been using the DAAB part of the Enterprise Library at my current job. One of the advantages of using this library is that you can write ANSI standard SQL, and it should work with any Relational Database.
The problem with this is that if you want to use parametrized queries, T-SQL and PL-SQL use different prefixes in front of the parameters.
I saw this story over on DIGG today. There was a study done that shows that Oracle's database has more security flaws then SQL Server.
I will point out that I am biased. I have used both SQL Server and Oracle, and I prefer MS SQL Server. I have found it much easier to develop on SQL Server because of the client and integration tools.
The article also points out that there are many zero day exploits that Oracle has not fixed.
Oracle has released a free version of their database server software. It is called Oracle Express. It looks like a competitor to the SQL Server express and MySQL products.
It will work with Redhat and Windows. No Mac installer yet.
