Re: rules and default values - Mailing list pgsql-hackers

From Neil Conway
Subject Re: rules and default values
Date
Msg-id 20020415144254.39921398.nconway@klamath.dyndns.org
Whole thread Raw
In response to Re: rules and default values  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
On Mon, 15 Apr 2002 14:25:28 -0400
"Tom Lane" <tgl@sss.pgh.pa.us> wrote:
> Awhile back I said:
> > nconway@klamath.dyndns.org (Neil Conway) writes:
> >> In other words, when the insert statement on the view is transformed by
> >> the rule, the "default value" columns are replaced by explicit NULL
> >> values (which is the default value for the columns of the pseudo-table
> >> created by CREATE VIEW). Is this the correct behavior?
> 
> > It's correct, from the point of view of the rule rewriter, but that
> > doesn't make the behavior useful.
> 
> > What'd make sense to me is to allow defaults to be attached to the
> > view columns, say by doing ALTER TABLE ADD DEFAULT on the view.
> > Unfortunately that won't do much in the current implementation,
> > because such defaults will never get applied (the planner certainly
> > won't see them as applicable).
> 
> > Maybe inserting defaults should be the first phase of rewriting, just
> > before rule substitution, rather than being left to the planner as it
> > is now.  We took it out of the parser for good reasons, but perhaps
> > we moved it too far downstream.
> 
> I recently moved the default-insertion phase to fix a different bug,
> so this is now possible.  Given the attached patch, it actually works.

Great!

> However I have not applied the patch because it needs (a) pg_dump
> support and (b) documentation, neither of which I have time for at the
> moment.  Anyone want to pick up the ball?

Sure, I'll do this stuff.

Cheers,

Neil

-- 
Neil Conway <neilconway@rogers.com>
PGP Key ID: DB3C29FC


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