External databases are great things, but they are not a panacea. It is nice, at university, to think of a database as that separate black box that data goes into and out of and is all nicely managed for you.

Having seen databases used in different companies (such as Sybase, Oracle, PostgreSQL, MySQL, and Informix) and used a few, although being no DBA myself, I've come to realise that each DB behaves in different ways and every single one needs a lot of hand holding.

It pays to keep a close eye on a new system. The problem is that your use of a database can be just as much of a problem as the application you just wrote and (rightly so) assume to be the most likely source of the fault compared to this off-the-shelf application that's a mature product.

I liked your post, have upvoted it, as I think it's a great learning experience any time you realise a fault is somewhere you didn't think before. Well done!