Alternative DB's

Freeware/Open Source relational databases is developing and the number of both commercial and free databases and tools is constantly increasing. Check my Database Listing for more database systems.

PosgreSQL is an advanced and interesting database if you are looking for a freeware substitute for a commercial database. Documentation and education is the week point.

The most popular DB for Internet application is probably MySQL even if it lacks some vital functions like more complex SQL-constructs, views and transactional consistency (some features fixed in version 5 though). A more in depth comparison is at here

Java databases is an interesting choice for some applications and small projects.
There are a couple of software-packs of different complexity around.
Just look at Hypersonic SQL/hsqldb is a nice Java-based and configurable database. Free and Open source SQL database. Completely written in Java so it can run as Client, client-server or server-side only. And it naturally has a JDBC-interface.
Another one is McKoi open source SQL database A very interesting and developing database. is tinySQL still another Rdbms, maybe not as ambitious as some other ones, but small.

Links to my Database software Database Listing
Use my Oracle SQL guidelines if you find them useful.

Database Design

Database design is out of fashion at the moment and so is tools for database design and system structuring.

Relational databases software today is complex and has a lot of features. You might easily get lost in this feature full world so it is important that you use the functions and features with care and think of what is important for your system and crucial to the system, so that you can live with it for years.
It is a piece of cake to create a database. There are a lots of tools to help you as well, and it is easy to create a database structure that:

But It requires a lot of work to create a data structure that will give you the advantages that you demand of a modern database system, and that can be usable for many years. It should be expandable, scalable and flexible enough to let your business change and still use your informational system. If the system and data design is done correctly the result can be a system that is easily managed and behaves well under stress conditions for a long time.