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 anothe=
r type.
Is there a way to make values of "undefined" type pass through the SELECT D=
ISTINCT filter (getting checked for uniqueness) but remain "undefined" if a=
ll 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 introducin=
g implicit type casts.