Re: Recursive Queries

Le jeudi 25 janvier 2007 à 12:12 -0500, Gregory Stark a écrit :

> "Joshua D. Drake" <jd(at)commandprompt(dot)com> writes:
>
> > > That's basically how the existing patch approached the problem. It invents a
> > > new type of join and a new type of tuplestore that behaves this way. This has
> > > the advantage of working the way Oracle users expect and being relatively
> > > simple conceptually. It has the disadvantage of locking us into what's
> > > basically a nested loop join and not reusing existing join code so it's quite
> > > a large patch.
> >
> > I believe our Syntax should be whatever the standard dictates,
> > regardless of Oracle.
>
> Well the issue here isn't one of syntax. The syntax is really an orthogonal
> issue. The basic question is whether to treat this as a new type of plan node
> with its behaviour hard coded or whether to try to reuse existing join types
> executing them recursively on their output. I can see advantages either way.
>
> As far as the syntax goes, now that I've actually read up on both, I have to
> say: I'm not entirely sure I'm happy IBM won this battle. The Oracle syntax is
> simple easy to use. The IBM/ANSI syntax is, well, baroque. There's a certain
> logical beauty to it but I can't see users being happy trying to figure out
> how to use it.
>

I agree with THAT, it's clear that WITH RECURSIVE is more standard...
but for the SQL developper CONNECT BY is a paradise... the syntax is
clear and powerful... That's why we've chosen to developp our queries
with that (using the connectby() function and the evgen potemkin.'s
patch (http://gppl.moonbone.ru/)

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