Re: Oracle 11g Virtual Columns?

From: Robert Klemme <shortcutter_at_googlemail.com>
Date: Mon, 19 Jan 2009 20:42:04 +0100
Message-ID: <6tk3cgF9o1m0U1_at_mid.individual.net>

On 19.01.2009 09:40, Mladen Gogala wrote:
> On Sun, 18 Jan 2009 15:34:34 -0800, hpuxrac wrote:
>

>> I guess one way is to have a virtual column and be able to build an
>> index on it.

>
> It was called a "functional index" back in the 8i version.

With the added benefit that you can get the value without using the expression which can make your life a lot simpler depending on the expression. Basically you get an alias for the expression which makes treating columns more uniform than before. Also, this opens some migration paths (e.g. you have a column that is rendered redundant by a design change, then you can simply replace it by a virtual column saving the space).

Btw, MS SQL Server has this quite a long time already. It's called "computed column" over there. SCNR :-)

Kind regards

        robert

-- 
remember.guy do |as, often| as.you_can - without end

Received on Mon Jan 19 2009 - 13:42:04 CST