Question: We all have our favourite database. If you look objectively at your chosen database, what drawbacks does it have and what could be improved?

The rules:

* One reply per drawback with;
* a short description of the limitation, followed by;
* a more detailed description, an explanation of how it could be done better or an example of another technology that does not have the same limitation.
* Do not diss any database that you haven't used extensively. It is easy to take potshots at other technologies but we want to learn form your experience, not your prejudice.

Answer: 
I love the flexibility of sequences in Oracle as compared with other databases autoincrements, but the inability to set seq.nextval as a default for a pk column is somewhat annoying, and must be trivial to fix.
**Database** MySQL

**Defect** Foreign Keys supported only on some table types

**Description**

Enough said. It has obvious maintenance implications.

From the [MySQL manual](http://dev.mysql.com/doc/refman/5.0/en/innodb-foreign-key-constraints.html)

> 
> Foreign keys definitions are subject to the following conditions:
> 
> 
> * Both tables must be InnoDB tables and they must not be TEMPORARY tables.
> 
> 
> 

And [here](http://dev.mysql.com/doc/refman/5.0/en/ansi-diff-foreign-keys.html):

> 
> For storage engines other than InnoDB, MySQL Server parses the FOREIGN KEY syntax in CREATE TABLE statements, but does not use or store it.
> 
> 
> 

This does not happen with any other major DB.