Re: [HACKERS] SELECT BUG

Tom Lane ha scritto:

> =?iso-8859-1?Q?Jos=E9?= Soares <jose@sferacarta.com> writes:
> >> When I "explain" this, I see that I am getting a mergejoin plan.
> >> Are you getting a hash join, perhaps?
>
> > Yes.
>
> > prova=> explain select  mcode, dcode from master m, detail d where
> > mcode=dcode;
> > NOTICE:  QUERY PLAN:
> >
> > Hash Join  (cost=156.00 rows=1001 width=24)
> >   -> Seq Scan on detail d  (cost=43.00 rows=1000 width=12)
> >   -> Hash  (cost=43.00 rows=1000 width=12)
> >       -> Seq Scan on master m  (cost=43.00 rows=1000 width=12)
> >
> > EXPLAIN
>
> OK, do this:
>
> update pg_operator set oprcanhash = 'f' where oid = 1054;
>
> and I think you'll be OK.  I will put that change into the sources.
>
>                         regards, tom lane
>
> ************

Yes, Tom, now it works, but...
Informix gives me a different result. Who is right ?


prova=> select  mcode, dcode from master m, detail d where mcode=dcode;
mcode|dcode
-----+-----
(0 rows)

prova=> update pg_operator set oprcanhash = 'f' where oid = 1054;
UPDATE 1
prova=> select  mcode, dcode from master m, detail d where mcode=dcode;
mcode      |dcode
-----------+----------------
a1         |a1
a13        |a13
a13        |a13
(3 rows)


INFORMIX:
SQL:   New  Run  Modify  Use-editor  Output  Choose  Save  Info  Drop
Exit
Run the current SQL statements.
----------------------- hygea@hygea ------------ Press CTRL-W for Help
--------
mcode dcode
a1    a1
a13   a13


José