[EzGraphs]

There are probably some useful applications for this, but I am not really a fan of databases supporting complex data types. It's not because of a commitment to any particular normal form or theoretical construct. It is because on a project that involves multiple developers over a period of time, this sort of special functionality provides "surprises" that are not terribly pleasant.

- Nonstandard SQL is required

- Database specific functions are used

- Later developers can be confused by the use of a non-standard data type

- SQL Commenting does not happen much in practice in my experience

- Array data can be handled using existing SQL constructs, so it is never an absolute necessity

- Other languages are better equipped for handling the data types (in my fuzzy subjective assessment)

My experience is mostly with Oracle, which has been adding various data types for years (XML, Objects, Arrays, etc). I can't think of a specific case where their use proved to be a real specific benefit to a project... though the usual argument is improved performance.