Re: full featured alter table?

>>It'd be nice if it allows you to change the type from varchar(40) 
>>to varchar(20) if you don't have any data that is larger than varchar(20). 
> 
> Yeah, and then an application comes in and wants to write more than
> 20 chars ...

why should i define a column as varchar(20) and should than want to 
write more data than that?
i'd only define it as varchar(20) if i'm sure that 20 chars are enough.

> well, i dont like such size limitations at all - i'm using "text" instead.
> what about efficiency ? does it bring _anything_ to limit the size
> of varchar fields ?

well - than use text instead of varchar.