>>>>Hi all,
>>>>
>>>>When adding records with views I don't where is the best place to create the primary key, the view or the table.
>>>>I generate the PK with a newId() function, and I don't know whether to put it on the default value of the view field or the default value of the table itself. I "have" to put the code in the table just in case I don't use the view; so I thought that if I inserted the newId() in the view I would end up creating twice the PK (and wasting PK), but I tested and it was not the case. So I don't really know what should I do from a "good practices" point of view.
>>>>
>>>>TIA,
>>>>Javier.
>>>
>>>Javier,
>>>Personal suggestion: Both and mark key updatable. A newid() function returning GUID fit into this perfectly. Key would be 'at least' 16 bytes so a trade off there.
>>>PS:SQL server NewID() function returns a GUID.
>>>Cetin
>>
>>Cetin, thanks for the answer. I think I'm going your way, but I will not use GUIDs. I don't like them because of performance issues (in some informal testing I made, SQL selects where 20%-30% slower using 16 bytes GUIDs than 4 byte integers).
>
>Javier,
>As I said it's a trade off. On the long run you might be glad you wasted 20-30% performance (I didn't test at all in depth).
>Integer keys are not for replication and if it's never a possibility to merge data from different sources then integers might do it very well.
>Cetin

In this solution I don't plan to merge data from different locations (I know, I know, whenever you say "I don't plan" you end up doing it); and performance is somewhat a priority.

What I found in my informal testings is that performance degrades as the PK fields grow in size. I found that a 4 byte character was pretty similar to a 4 byte integer. But as the size of the field grew over 7 bytes you started to notice less performance.
I have always taken a difference of less than 10% in performance as not noticiable by the user. This 10% is not a scientific figure, it is an approximation I did. I would like to know if there is a paper on this. So as long as performance gets into this 10% I don't sacrifice it. But 20%-30% was too much in this project.

Thanks for your answer,
Javier.