Peter Eisentraut <[EMAIL PROTECTED]> writes:
> Am Freitag, 30. September 2005 09:03 schrieb Oliver Siegmar:
>> - 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.

Note also that the "functional dependencies" stuff was added in SQL99.
Postgres' current behavior corresponds to the SQL92 standard.

                        regards, tom lane

---------------------------(end of broadcast)---------------------------
TIP 9: In versions below 8.0, the planner will ignore your desire to
       choose an index scan if your joining column's datatypes do not
       match

Reply via email to