These tests pretty much confirmed what I already knew - both databases serve
quite well for the vast majority of web sites out there. Both are actually
extremely fast when compared to desktop databases like FileMaker and MS Access.
Both are now free and supported by an active developer community.
To choose between the two databases, you first need to understand your
scalability limits and whether you need the transaction support of Postgres or
the large-text-area support in MySQL. You may need both, in which case you have
to wait for future stable releases of both databases.
It's interesting to note that the two databases appear to be converging to meet
in the middle somewhere. While MySQL is working on adding transaction support
and slowly adding features like subselects, Postgres is making headway in the
performance and stability departments.
Finally, for the hardest-core developers, Postgres could be pretty slick.
Foreign keys, views, subselects, and transactions can all be pretty cool -- if
you need them and you will make any use of them. If you don't need them or
won't use them, then you're probably better off with MySQL and its superior