Re: Tuple data

On Sunday 17 December 2000 19:10, Hiroshi Inoue wrote:
> Hannu Krosing wrote:
> > Tom Lane wrote:
> > >> ALTER ADD COLUMN doesn't touch any tuples, and you're right that it's
> > >
> > > critically dependent on heap_getattr returning NULL when an attribute
> > > beyond the number of attributes actually present in a tuple is
> > > accessed. That's a fragile and unclean implementation IMHO --- see past
> > > traffic on this list.
> >
> > Short of redesigning the whole storage format I can see no better way to
> > allow
> > ALTER ADD COLUMN in any reasonable time. And I cna see no place where
> > this is
> > more "fragile and unclean implementation" than any other in postgres --
> > OTOH it is quite hard for me to "see the past traffic on this list" as
> > my
> > "PgSQL HACKERS" mail folder is too big for anything else then grep ;)
>
> I don't remember the traffic either.

This is kind of a lame comment, but the pgsql- mail lists are archived at
www.mail-archive.com. You can search lots of archived mail lists there.

> IIRC,I objected to Tom at this point in pgsql-bugs recently.
> I think it's very important for dbms that ALTER ADD COLUMN
> touches tuples as less as possible.
>
> Regards.
> Hiroshi Inoue

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