Martin Mueller <[email protected]> writes:
> Are there performance issues with the choice of 'text' vs. varchar and some
> character limit? For instance, if I have a table with ten million records
> and text fields that may range in length from 15 to 150, can I expect a
> measurable improvement in response time for using varchar(150) or will text
> do just or nearly as well.
There is no situation where varchar outperforms text in Postgres.
If you need to apply a length constraint for application semantic
reasons, do so ... otherwise, text is the native type. It's
useful to think of varchar as being a domain over text, though
for various reasons it's not implemented quite that way.
regards, tom lane
