Re: dropping a column in a production database

From: Bindu <>
Date: Wed, 2 Jul 2008 09:01:33 -0700 (PDT)
Message-ID: <>

On Jul 2, 9:42 am, Mark D Powell <> wrote:
> On Jul 2, 8:38 am, yossarian <> wrote:
> > Ed Prochak wrote:
> > > It is safe in the sense that it will do exactly what you ask. Any data
> > > in that dropped column will be gone (forever if you do not have it in
> > > a backup). Note that any applications that used that column will need
> > > to be rewritten. Packages, functions and procedures dependent on that
> > > column will become invalid and need to be rewritten. It's all standard
> > > stuff.
> > OK, thank you. I was just wondering about unexpected side effects.
> > Kind regards, Y.
> As Ed said, just standard stuff.  As long as you modify any code that
> uses the column to no longer reference it prior to the drop column
> operation you should be fine.  If the table is large the drop may take
> a while but since the second version after the feature was introduced
> Oracle auto-commits the change however the 10g SQL manual says the
> default is now 512 so you might want to change the commit frequency.
> HTH -- Mark D Powell --

If you are not really sure, may be you can mark the column unused first

ALTER TABLE table_name SET UNUSED (column_name);

Then test your application and if everything works as expected, drop the column at a later time. Received on Wed Jul 02 2008 - 11:01:33 CDT

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