Re: SQL99 CREATE TABLE ... (LIKE parent_table)

Where did we leave this patch?

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Rod Taylor wrote:
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> On Mon, 2003-05-12 at 10:59, Tom Lane wrote:
> > Rod Taylor <rbt@rbt.ca> writes:
> > > Quick patch to add the subject.  Restructures all inheritance to consist
> > > of a few flags to indicate which structures we want to inherit
> >
> > I think overloading the inheritance mechanism to serve this purpose is a
> > bad idea.  It complicates and confuses a significant amount of code
> > that's already pretty confusing (no, I don't believe you found it all).
> > It'd be better to have a localized bit of code that processes LIKE by
> > generating a ColumnDef schema list.
>
> That can be done without much of an issue.  Much of the code in
> MergeAttributes will be duplicated in this new routine.
>
> I'll conduct the transform of LIKE to ColumnDef list within the
> transformCreateStmt where the rest of the transformations take place.
>
> > > Yes, I wish to add an option to allow check
> > > constraints to be carried over despite the below note from Sect. 11.3:
> >
> > > NOTE 234   <column constraint>s, except for NOT NULL, are not included
> > > in NCi; <column constraint definition>s are effectively transformed to
> > > <table constraint definition>s and are thereby also excluded.
> >
> > Why is it a good idea to ignore the express requirement of the spec?
> > (I'm not saying it's not a good idea --- that note seems a little odd
> > to me too --- but presumably the spec writers had some reasons for
> > doing it that way.  I'd like some justification for not doing it their
> > way.)
>
> If you consider LIKE is allowed to inherit an IDENTIFIER, which is a
> sequence based column with the intent that it will be a primary key,
> then allowing inheritance of CONSTRAINTS (via an optional flag INCLUDING
> CONSTRAINTS -- default is per spec) only makes sense.
>
> UNDER (IHERITS) appears to allow constraints to be inherited.
>
> --
> Rod Taylor <rbt@rbt.ca>
>
> PGP Key: http://www.rbt.ca/rbtpub.asc
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