"Jim C. Nasby" <jnasby@pervasive.com> writes:
> About the only reason I use CHAR in other databases systems is when I
> know that the field will always contain the same amount of data, ie:
> storing a SHA1. In these cases it's silly to have a 4 byte overhead to
> store length. I really wish CHAR in PostgreSQL worked this way, so it
> would be a welcome addition to have a type that did work this way. In
> fact, I'd argue that CHAR should be made to work that way, and what's
> currently called CHAR should be renamed for those who wish to use it.
This argument falls flat when you consider that the width of a CHAR
entry is measured in characters, not bytes, and therefore its physical
size is not fixed even if its logical width is.
regards, tom lane