Re: EJB w/ different DB's

[Elias Martensson]

On Fri, 7 Jan 2000, Magnus Rydin wrote:

> Foreign keys are good for making sure your data is consistant, for example you
> cant reference a bank account that does not exist.
> They are also good for defining delete rules, such as if this order is deleted,
> make sure all orderrows are deleted too.
> Correctly defined, they also speed up searching over multiple tables (if
> needed).

That reminds me of another important feature that mysql is lacking:
Constraints.

> But if your system does not need this (now or in the future), Databasesystems
> like MySQL is excellent.

Under what cicumstances is mysql better than one of the four? Or even
PostgreSQL?