Re: When to use Updateable View ?

On Sat, 30 Sep 2006 22:04:29 -0700, DA Morgan wrote:

> HansF wrote:
>

>> A view should represent a business access to the data.  For example the
>> view might provide the complete purchase order information, rather than
>> the 'purchase order header' and 'line items' normalized tables.  

No argument.

I gave an example of a 'business oriented view'. It was not intended to be directly updateable. I did mention the possibility for InsteadOf triggers later in the post.

My discussion was simply:  

1. A view should have a meaning.
2. If it has a meaning, it can be used for update (although InsteadOf may be required).
3. When comparing performance, look at the entire operation from initial select, not just the actual update statement.

A digression perhaps, but to expand on my point #1 ... I firmly believe that we, as analysts, missed the boat years ago. The typical analyst transforms entities to 3NF and beyond, and then implements as tables. I think this often results in loss of the business meaning that was captured. I think that the VIEW implements the proper transformation between the logical and physical model.

-- 
Hans Forbrich   (mailto: Fuzzy.GreyBeard_at_gmail.com)   
*** Feel free to correct me when I'm wrong!
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