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

From Don Baccus
Subject Re: AW: ALTER TABLE DROP COLUMN
Date
Msg-id 3.0.1.32.20001013131403.017e2b98@mail.pacifier.com
Whole thread Raw
In response to AW: ALTER TABLE DROP COLUMN  (Zeugswetter Andreas SB <ZeugswetterA@wien.spardat.at>)
Responses RE: AW: ALTER TABLE DROP COLUMN  ("Hiroshi Inoue" <Inoue@tpf.co.jp>)
List pgsql-hackers
At 04:23 PM 10/12/00 +0200, Zeugswetter Andreas SB wrote:

>My conclusion would be that we need both:
>1. a fast system table only solution with physical/logical column id
>2. a tool that does the cleanup (e.g. vacuum) 

Oracle provides both styles of "drop column" - the "hide the column's
data and make it logically disappear" style, and the "grind through
and delete all the data as well as make the column disappear from
view".  So there's evidence of a need for both styles.

If you choose the "hide the data" style, I don't know if you can later
recover that space.

However, despite the above I think a 2x "grind through and remove the
data" DROP COLUMN would be a welcome first addition, and would meet the
needs of a very high percentage of the current user base.  A future
option to just hide the data would most likely be welcome, too.



- Don Baccus, Portland OR <dhogaza@pacifier.com> Nature photos, on-line guides, Pacific Northwest Rare Bird Alert
Serviceand other goodies at http://donb.photo.net.
 


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