Re: Where is a mistake?

Ed Loehr <eloehr@austin.rr.com> writes:
>> I have PGSQL v 6.5.3.

> Mistake #1:  using 6.5.3 instead of 7.0  :)

Check --- 7.0 has a lot of bugfixes in this area.

> Mistake #2:  aggregates are not supported in views  :(

Not so much aggregates as GROUP BY.  In this case he's attempting to do
two levels of aggregation and grouping, one in the view and the other
in the calling SELECT.  There's no way to make that work in the current
implementation of views, because it can't be rewritten into a single
legal-SQL statement.  I trust that 7.0 won't crash, but it will tell you
it can't do it.

We're planning to fix this for 7.2, by redoing the querytree
representation so that views can be handled as separate processing steps
in a pipeline, rather than as a rule that transforms the original query.
It's not a small job though :-(
        regards, tom lane