Re: Can Oracle drop a column?

From: Michael Nolan <nolan_at_inetnebr.com>
Date: 1997/05/27
Message-ID: <5merjg$iu1$1@falcon.inetnebr.com>#1/1

dmmatt_at_monsanto.com (D.M. Mattix) writes:

>If you underestimate the size of a varchar column and need to extend it
>you can add a new larger column and (using SQL) copy the data to it
>but you cannot get rid of the old column.

I'm not sure if the above comment is referring to Oracle or Rdb. In Oracle, a column can be increased in size in place but not decreased in size unless all rows for that column are NULL. In my experience, this operation can take a long time depending on the size of the table and the data type of the column (presumably because Oracle is rewriting all of the rows), but when done on a VARCHAR2 column it is nearly instantaneous.

---
Mike Nolan

Received on Tue May 27 1997 - 00:00:00 CDT