Re: [SQL] Wierd stuff

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От Mario Jorge Nunes Filipe
Тема Re: [SQL] Wierd stuff
Дата
Msg-id 384BBEF2.B6CB6CDD@neptuno.uevora.pt
обсуждение исходный текст
Ответ на Re: [SQL] Wierd stuff  (Tom Lane <tgl@sss.pgh.pa.us>)
Ответы Re: [SQL] Wierd stuff  (Tom Lane <tgl@sss.pgh.pa.us>)
Список pgsql-sql
Tom Lane wrote:
> Actually, I think that this may indeed be the root of the problem.
> I killed several bugs in cross-data-type joins a while back ... for
> example, IIRC pre-6.5 Postgres thought it could use hash joins for
> cross-data-type equality operators, but that doesn't work properly in
> general.  Mario, what does EXPLAIN show about how the join query is
> being done?
First of all: sorry for the late reply, but with the weekend and all...
To awnser your question... EXPLAIN shows this:
sac=> explain select c.nome from aluno a, concelho c where
sac-> a.concelho_naturalidade=c.codigo and a.numero_aluno=13792;
NOTICE:  QUERY PLAN:

Hash Join  (cost=27.44 size=164 width=18) ->  Seq Scan on c  (cost=13.16 size=308 width=16) ->  Hash  (cost=0.00 size=0
width=0)      ->  Index Scan on a  (cost=2.05 size=2 width=2)
 

EXPLAIN
Upgrading at this point might be complicated, but sooner or later i
will have to upgrade...

--        Mario Filipe        mjnf@uevora.pt       http://neptuno.sc.uevora.pt/~mjnf


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