"Josh Berkus" <josh@agliodbs.com> writes:
> In some databases, yes. However, in PostgreSQL, there is no
> performance difference between CHAR, VARCHAR, and TEXT. So use what's
> appropriate for the data being stored.
In fact, char() is probably *worse* than the other alternatives, at
least for data that doesn't have a clearly defined length, because
it forces blank-padding on you.
I'd use char(N) for US postal abbreviations (state = char(2), etc)
and not a lot else. If you have an *error checking* reason to use
char(N), then use it. If you think you are getting a performance
improvement, then you are far out in left field.
regards, tom lane
