Re: Using views inside a View

On Thu, 17 Feb 2005 04:08:37 -0800, muneerhassan wrote:

> Hi,
>
> Is there any performance problem when using a view inside a view. I
> dont find any performance issue as such. Our client is insisting that
> their standard wont allow to use views inside views. But i feel by
> using views inside views, developers are finding it more easy to write
> bug free queries which are more logicaly organized. Is there any
> advantage or draw backs in following this practice. Pls shed light on
> this .
>
> Thanks
> Muneer

You client is absolutely correct - I found in Oracle version 5 and early Oracle version 6 there were significant performance problems that arose from nested views.

However, many of these were resolved in Oracle 7. If your client is using any currently supported version of Oracle, there should be no hesitation in nesting views - provided suitable supporting documentation describing their purpose and implementation is provided.

Seems like your client had standards created some time ago, and no one was smart enough to keep on top of them.

Since only money talks, you probably want to get a copy of Thomas Kyte's "Effective Oracle by Design" and implement his timing routines - then prove to your client that there is no runtime impact to nested views. A ROI case can then be generated to prove that developer efficiency is actually reducing client's costs.

(By the way, tell them they can use the Cost Based Optimizer as well <g>)

Hurray for myths and their thoughtless perpetuation! /FGB Received on Thu Feb 17 2005 - 06:27:32 CST