On 11/16/07, Reg Me Please <regmeplease@xxxxxxxxx> wrote:
> Il Friday 16 November 2007 08:33:14 Tom Lane ha scritto:
> > Let me try to explain one more time. You propose allowing
> >
> > select ... from
> > table1 join table2 on table1.x = table2.y
> > limit table1.z
> >
> > Now this would be somewhat well-defined if there were only one row in
> > table1, or if there were many rows but they all had the same value
> > in column z. But what if that's not the case? If there are multiple
> > possible values for z then the query is just not sensible.
> tmp=# SELECT * from nextval( (select seq from seqs) );
> ERROR: more than one row returned by a subquery used as an expression
This is a subselect, not a column from the query itself. Completely
different thing.
---------------------------(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
