Re: AW: AW: ALTER TABLE DROP COLUMN - Mailing list pgsql-hackers

From Bruce Momjian
Subject Re: AW: AW: ALTER TABLE DROP COLUMN
Date
Msg-id 200010130907.FAA23006@candle.pha.pa.us
Whole thread Raw
In response to AW: AW: ALTER TABLE DROP COLUMN  (Zeugswetter Andreas SB <ZeugswetterA@wien.spardat.at>)
Responses Re: AW: AW: ALTER TABLE DROP COLUMN  (The Hermit Hacker <scrappy@hub.org>)
Re: AW: AW: ALTER TABLE DROP COLUMN  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
[ Charset ISO-8859-1 unsupported, converting... ]
> > we bite the bullet to the extent of supporting a distinction between
> > physical and logical column numbers, then ISTM there's no strong need
> > to do any of this other stuff at all.  I'd expect that an inserted or
> > updated tuple would have a NULL in any physical column position that
> > doesn't have an equivalent logical column, so the space cost 
> > is minimal
> > (zero, in fact, if there are any other NULLs in the tuple).  Over time
> > the space occupied by deleted-column data would gradually go away as
> > tuples got updated.
> 
> This said, I think Hiroshi's patch seems a perfect starting point, no ?

Having phantom columns adds additional complexity to the system overall.
We have to decide we really want it before making things more complex
than they already are.

--  Bruce Momjian                        |  http://candle.pha.pa.us pgman@candle.pha.pa.us               |  (610)
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