Re: Oracle 11g Virtual Columns?
From: hpuxrac <johnbhurley_at_sbcglobal.net>
Date: Sun, 18 Jan 2009 15:34:34 -0800 (PST)
Message-ID: <b9f97558-a6c8-43c0-b77b-6bdd3beb504b_at_o4g2000pra.googlegroups.com>
On Jan 18, 5:26 pm, zigzag..._at_yahoo.com wrote:
> I have read various articles on virtual columns? I still do not
> understand their advantages other than they save some disk space, One
> can put logic of virtual columns in a trigger which will save
> information in a real column. Real column will need some additional
> disk space, but it will save some cpu time when one is doing slelects
> on “virtual” columns.
Date: Sun, 18 Jan 2009 15:34:34 -0800 (PST)
Message-ID: <b9f97558-a6c8-43c0-b77b-6bdd3beb504b_at_o4g2000pra.googlegroups.com>
On Jan 18, 5:26 pm, zigzag..._at_yahoo.com wrote:
> I have read various articles on virtual columns? I still do not
> understand their advantages other than they save some disk space, One
> can put logic of virtual columns in a trigger which will save
> information in a real column. Real column will need some additional
> disk space, but it will save some cpu time when one is doing slelects
> on “virtual” columns.
Well of course triggers are evil but views can also serve the same purpose.
As I remember Tom Kyte was excited about the virtual columns so there must be some benefits.
I guess one way is to have a virtual column and be able to build an index on it. Received on Sun Jan 18 2009 - 17:34:34 CST