> > But there can be only one... primary key per table (hence the name
> > 'primary', and thus there can be only one auto_increment)
> 
> What's surprising is that AUTO_INCREMENT must be on a primary key only.

Nah, its not surprising at all - in fact its quite clever.

The whole point of a primary key is uniqueness - if you have an auto 
increment column, guaranteeing uniqueness, why wouldnt it be the primary 
key? Why would you ever want an auto increment column which is not the 
primary key?

You can always create indexes on other fields at your leisure.

> 
> <troll> of course, postgresql is already in woody.... </troll>
> Seriously, this is where mysql 3.x runs into problems - if you want to 
> do anything more than the basics.  The only thing I haven't got 
> postgresql to do yet is the FULLTEXT INDEX function of MySQL.
> 
> You may wish to consider postgresql as an alternative to using mysql for 
> your web-based database. There really isn't a downside, and posgresql is 
> a far more full-featured database.
> 

yes, yes it is. and soon we will have nicer replication and hot 
backups/point in time recovery :D

