Oracle XE or SQL Server Express
I would go for the SQL Server Express solution, unless you absolutely have to use a feature in Oracle that SQL Server does not have and you have no usable workaround.
Example of Oracle's strengths:
- Analytical Functions in Oracle ROCK!
- PL/SQL is better than T-SQL.
- If you're going to scale up the system to 1,000's of users all updating the same small dataset
- You scale upto multi-TB databases,
- You need to scale to need big numbers of CPU's in your server (over 8).
- need instant failover (RAC)
- you really cannot afford to lose a transaction.
Maybe you can tell, I'm a big Oracle fan! But I think that Oracle Express is a commercial reaction to SQL Server Express and I don't think Oracle really deep deep down likes it.
- You know with SQL Server that there is an upgrade path (SQL Server 2008 is soon) plus service packs.
- SQL Express is also more "install and forget" than Oracle.
- and it will integrate better with your IDE (if your using .NET)
In terms of speed, both are going to be lighting quick with such a small dataset size.
It would be hard to argue either way given the needs you outlined, that either would shine over the other.
What I will say is this:
- You say you are already familar with SSExpress, then that is a good reason to stick with it
- IMHO the tools with SSExpress are superior and easier to use than the Oracle equivalent
That said, I have much more experience with SS than Oracle so YMMV.
Sorry, no link, but one advice. Because we support Oracle and SQL Server, I know that getting fixes for the 'normal' Oracle database, is not something what I call fun. You have to pay for it, and if you have no tool which updates your Oracle system for you, it's a pain in the a.., if you ask me. Check out how the Oracle XE is supported with updates/fixes. I don't know, I only use the 'normal' Oracle (Developer) database.