RE: views on views on views
Date: Thu, 26 Mar 2009 13:48:32 -0500
Just out of curiosity, I'm wondering if there a certain characteristics in a data model that leads people to do this kind of thing.
Where I work, typically, at least one of the views in the hierarchy of views is used to fill in gaps of events across defined time periods. So they'll create an initial view to fill in those gaps (that may be based on a view pulling in the details of what they are wanting) and then usually stick some sql on top of that to restrict the results based on specific time periods among other things.
Has anyone else noticed this kind of thing?
[mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Ram Raman Sent: Thursday, March 26, 2009 1:35 PM
Subject: Re: views on views on views
I was planning to open the exact topic a week ago, but was too busy. One of our users (you read it right) wants to build views that are multi layered like Chris talks about. I tried to talk about performance, she mentioned that it is ok and that she stopped at 9th level, ie 9 layers of view on top of view. IT was initially successful in preventing that, but apparently she used her clout and is having the view built :(
It is a good time to discuss the alternatives. With my knowledge, I can think of 1) Rewrite of the SQL 2) Materialized views.
Others can correct or add to it.
On 3/26/09, Lyndon Tiu <ltiu_at_alumni.sfu.ca> wrote:
On Thu, 26 Mar 2009 12:55:44 -0400 mwf_at_rsiz.com wrote:
> That is my understanding of what you wrote. Please let me know if I
> wrong, because I'm stumped about what else you could mean, by "That's
> ..." Oh, and I definitely disagree, if that is indeed your meaning.
Of course not.
-- Lyndon Tiu -- http://www.freelists.org/webpage/oracle-l CONFIDENTIALITY NOTICE: This message is intended for the use of the individual or entity to which it is addressed and may contain information that is privileged, confidential and exempt from disclosure under applicable law. If the reader of this message is not the intended recipient or the employee or agent responsible for delivering this message to the intended recipient, you are hereby notified that any dissemination, distribution or copying of this communication is strictly prohibited. If you have received this communication in error, please notify us immediately by email reply. -- http://www.freelists.org/webpage/oracle-lReceived on Thu Mar 26 2009 - 13:48:32 CDT