Re: [HACKERS] Tuple data

[Hiroshi Inoue]

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. 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