Re: [HACKERS] subselects

> We are only going to have subselects in the WHERE clause, not in the
> target list, right?
> 
> The standard says we can have them either place, but I didn't think we
> were implementing the target list subselects.
> 
> Is that correct?

What about the HAVING clause?  Currently not in, but someone here wants
to take a stab at it.

Doesn't seem that tough...loops over the tuples returned from the group
by node and checks the expression such as "x > 5" or "x = (subselect)".

The cost analysis in the optimizer could be tricky come to think of it.
If a subselect has a HAVING, would have to have a formula to determine
the selectiveness.  Hmmm...

darrenk