MySQL Notes
A common problem in MySQL is the comparatively simple act of defining a TIMESTAMP column which has as its default value the timestamp at the time the record is created. In most databases this is simply a case of appending DEFAULT NOW() to the timestamp column.
Beginning with version 4.1.2 MySQL now supports this, albeit as an overlay to the slightly eccentric TIMESTAMP functionality, making life just that little bit easier.
The most prominent new feature of MySQL 4.1 is the introduction of subqueries (also known as subselects), a very welcome addition which brings MySQL's feature set a little closer to that of other databases.
It's possible to modify the way in which MySQL interprets certain parts of SQL, useful when porting queries from other databases. For example, the option PIPES_AS_CONCAT will persuade it to accept || as a concatenation operator rather than as a synonym for OR (see also gotcha 1.12). In 4.1 this facility has been extended considerably.
After a long testing period MySQL 4.1 has finally been declared production ready and is available for download. Representing a further incremental step in MySQL's steady advancement towards fully-fledged RDBMS-dom, it provides several sorely-missed features including sub-SELECTs.
It looks like MySQL are moving their mailing lists to a forum-based solution, currently in beta-testing. Whether these will completely replace the lists, or provided an alternative web-based interface, isn't yet clear.