On Mon, Jun 7, 2010 at 10:30 AM, Andy Balholm <a...@balholm.com> wrote: > Craig Ringer wrote: >> showing that your issue isn't actually with DISTINCT at all, but with Pg's >> unwillingness to *implicitly* cast a value of explict text type to another >> type. > > Is there a way to make values of "undefined" type pass through the SELECT > DISTINCT filter (getting checked for uniqueness) but remain "undefined" if > all the values supplied for the column are "undefined"? I don't know if the > internal design of SELECT DISTINCT and the type system would allow for this, > but if it would, it would take care of Farid's problem without introducing > implicit type casts.
The issue isn't what's technically possible, but what's least likely to lead to surprising behavior. This whole thread is basically about whether implicit casts to and from text are a good idea or not. The OP obviously thinks they are, and everyone else (whether they agree with the behavior or not) is trying to explain the reasons why we don't have them. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise Postgres Company -- Sent via pgsql-bugs mailing list (pgsql-bugs@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-bugs
