Re: how to drop a column?

"Dirk P.C. Wendt" <dpcw_at_xodox.org> wrote in message news:8oi4od$b013d$1_at_ID-25048.news.cis.dfn.de...
> Hello,
>
> "mike" <skyxx_at_263.net> schrieb:
> > i am beginer of oracle.i created a table ,now i must drop a column of
> > it,how can i do?
>
> that's not possible with Oracle smaller than version 8.1.5 I think:
>
> ALTER TABLE "Tablename" SET UNUSED ("Columnname") CASCADE CONSTRAINTS;
>
>
> Ciao, Dirk.
>

It's true that the command you describe is not available before 8.1.5.

However, that command is only half the story. It sets the column unused -it doesn't drop it. Once you've done what you've described, you should do an 'alter table drop unused columns' command to actually remove the data physically, and thus save yourself some physical disk space.

Regards
HJR
>
>
Received on Sun Sep 03 2000 - 03:30:51 CDT