Re: Improving GROUP BY?

Am Freitag, 30. September 2005 09:03 schrieb Oliver Siegmar:
> - Would it be possible to add a feature to PostgreSQL to allow grouping by
> unique identifiers only?
> - Is this requirement (all fields in GROUP BY) based on the SQL standard?

What you describe is called "functional dependencies" in the SQL standard.
(The query processor would recognize that the non-primary key columns
"functionally depend" on the primary key and therefore do not have to be
grouped separately.)  This is definitely a valid feature but PostgreSQL does
not implement it yet.

--
Peter Eisentraut
http://developer.postgresql.org/~petere/