Re: [OJB-developers] INNER JOIN syntax

[Jakob B. <jbr...@ho...>]

hi,

mysql also optimises joins
http://www.mysql.com/doc/L/E/LEFT_JOIN_optimisation.html
so i think we should stick to the JOIN-syntax wherever possible.

jakob

----- Original Message -----
From: "Matt Goodall" <ma...@po...>
To: <obj...@li...>
Sent: Monday, May 06, 2002 2:39 AM
Subject: Re: [OJB-developers] INNER JOIN syntax


> Hi,
>
> Just a couple of comments that might help ...
>
> PostgreSQL can produce more efficient access plans when the "inner join"
> syntax is used. I don't know whether that's true of other RDBMS. See
> http://www.postgresql.org/idocs/index.php?explicit-joins.html.
>
> Outer join syntax is completely different for different RDMBS. I thought
> these sorts of differences were already contained in RDBMS-specific
> classes. Can't they be used/extended to supply the correct inner join
> syntax too?
>
> Cheers, Matt.
>
> p.s. One day, i hope to stop lurking on this list. I'm just waiting for
> a project to use OJB with. ;-)
>
> On Sun, 2002-05-05 at 23:58, Oleg Nitz wrote:
> > Hi All,
> >
> > I propose to use equatilies in WHERE clause for INNER JOINs.
> > I mean that instead of
> > 1) SELECT ... FROM (A INNER JOIN B ON A.FK=B.ID) INNER JOIN C ON
B.FK=C.ID
> > we can generate
> > 2) SELECT ... FROM A, B, C WHERE A.FK=B.ID AND B.FK=C.ID
> > I don't know any RDBMS that doesn't support the 2nd syntax.
> > Does anybody knows one?
> > But I know the RDBMS that doesn't support the 1st syntax: HSQL.
> > To be more precise, HSQL does not support nested joins such as above.
> > Maybe it supports some other flavor of 1st syntax, but let's don't
increase
> > complexity if we can use 2nd syntax in all cases.
> > And the 2nd syntax seems shorter and simpler.
> >
> > Regards,
> >  Oleg
> >
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