Re: DROP COLUMN - Mailing list pgsql-hackers

From Tom Lane
Subject Re: DROP COLUMN
Date
Msg-id 11716.1026887176@sss.pgh.pa.us
Whole thread Raw
In response to Re: DROP COLUMN  (Hannu Krosing <hannu@tm.ee>)
Responses Re: DROP COLUMN  (Hannu Krosing <hannu@tm.ee>)
List pgsql-hackers
Hannu Krosing <hannu@tm.ee> writes:
> Also, as we have nothing like Oracles ROWNR, I think it will be quite
> hard to have colnums without gaps in the system views, so we could
> perhaps have a stopgap solution of adding logical column numbers  (
> (pg_attribute.attlognum) that will be changed every time a col is
> added/dropped just for that purpose.

[ thinks... ]  I don't believe this would make life any easier, really.
Inside the backend it's not much help, because we still have to look
at every single attnum reference to see if it should be logical or
physical attnum.  On the client side it seems promising at first sight
... but the client will still break if it tries to correlate the
logical colnum it sees with physical colnums in pg_attrdef and other
system catalogs.

Bottom line AFAICT is that it's a lot of work and a lot of code
to examine either way :-(
        regards, tom lane


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