Re: WITH RECURSIVE patches V0.1 TODO items

On Tue, May 27, 2008 at 12:40:58PM +0900, Tatsuo Ishii wrote:
> > > - cost of Recursive Scan is always 0
> >
> > This should probably be fixed, but it leads to problems like:
> >
> > > - infinit recursion is not detected
> > >
> > > * Tom suggested let query cancel and statement_timeout handle it.
> >
> > Right for this case. Is there some way to estimate this short of
> > a full-on materialized views implementation? I'm guessing we'd
> > need to be able to cache the transitive closure of such searches.
>
> I did some discussion with Gregory Stark and Michael Makes at PGCon.
> We tend to agree that very low constant cost for Recursive Scan
> (probably plain 0 is not good though) is not so bad, since this
> would emit plan which hashes the result of Recusive scan in a hash
> join plan which is probably not so bad for most cases.

It's good to know someone with the knowledge has some better estimate :)

> Also I talked with him that it would be nice we could have a kind of
> distributed source repository to co-develop patches.

This is just the kind of thing git
<http://wiki.postgresql.org/wiki/Working_with_Git> was designed for.

Who has tried it in your organization?

Cheers,
David.
--
David Fetter <david(at)fetter(dot)org> http://fetter.org/
Phone: +1 415 235 3778 AIM: dfetter666 Yahoo!: dfetter
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