
I read the transcript of the alter table drop column discussion (old
discussion) at http://www.postgresql.org/docs/pgsql/doc/TODO.detail/drop,
and I have something to add:

People mentioned such ideas as a hidden column and a really deleted column,
and it occurred to me that perhaps "vacuum" would be a good option to use.
When a delete was issued, the column would be hidden (by a negative/invalid
logical column number, it appears was the consensus). Upon issuing a
vacuum, it could perform a complete deletion. This method would allow users
to know that the process may take a while (I think the agreed method for a
complete delete was to "select into..." the right columns and leave out the
deleted ones, then delete the old table).

Furthermore, I liked the idea of some kind of "undelete", as long as it was
just hidden. This could apply to anything that is cleaned out with a vacuum
(before it is cleaned out), although I am not sure how feasible this is,
and it isn't particularly important to me.

Regards,
	Jeff

-- 
Jeff Davis
Dynamic Works
jdavis@dynworks.com
http://dynworks.com


Thu, 11 Jan 2001 18:48:36 PST
Jeff Davis <jdavis@dynworks.com>
alter table drop column

Added to TODO.detail/drop.

[ Charset ISO-8859-1 unsupported, converting... ]
> 
> I read the transcript of the alter table drop column discussion (old
> discussion) at http://www.postgresql.org/docs/pgsql/doc/TODO.detail/drop,
> and I have something to add:
> 
> People mentioned such ideas as a hidden column and a really deleted column,
> and it occurred to me that perhaps "vacuum" would be a good option to use.
> When a delete was issued, the column would be hidden (by a negative/invalid
> logical column number, it appears was the consensus). Upon issuing a
> vacuum, it could perform a complete deletion. This method would allow users
> to know that the process may take a while (I think the agreed method for a
> complete delete was to "select into..." the right columns and leave out the
> deleted ones, then delete the old table).
> 
> Furthermore, I liked the idea of some kind of "undelete", as long as it was
> just hidden. This could apply to anything that is cleaned out with a vacuum
> (before it is cleaned out), although I am not sure how feasible this is,
> and it isn't particularly important to me.
> 
> Regards,
> 	Jeff
> 
> -- 
> Jeff Davis
> Dynamic Works
> jdavis@dynworks.com
> http://dynworks.com
> 
> 


-- 
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 853-3000
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  +  Christ can be your backup.        |  Drexel Hill, Pennsylvania 19026

Fri, 12 Jan 2001 00:37:22 -0500 (EST)
Bruce Momjian <pgman@candle.pha.pa.us>
Re: alter table drop column