mesaalejandro
3/30/2007 11:56:00 PM
lmsiva,
Check the execution plan.
AMB
"lmsiva" <lmsiva@discussions.microsoft.com> wrote in message
news:89343BC7-0121-4E28-8B14-3369A5194F98@microsoft.com...
> Alejandro, Thanks for the reply. I am not very sure, if I understand it
> fully
> though. It is clear to me that views are like Macro definition but what I
> am
> not sure is, Is there a performance difference if I were to apply the data
> filters on each of the view and then join the data from individual views
> versus apply the filters on V1 fields on the combined view.
>
> In my case, the data filters that I apply on V1 can not be applied as is
> on
> the other views, I have to do some lookups.
>
>
> "Alejandro Mesa" wrote:
>
>> lmsiva,
>>
>> Unless those views are materialized ones, SQL Server will use the view's
>> definition because views are just that, a definition. Thinks about
>> macro-substitution, the concet is similar to that.
>>
>> AMB
>>
>> "lmsiva" wrote:
>>
>> > Hi,
>> > I have 3 views V1, V2, V3. I created a view V123, which combines
>> > three
>> > previous views. In the report I use the view V123. The report filters
>> > ( date
>> > and time and few more fields are applied only on the fields coming from
>> > V1 ).
>> > In this case, will the entire table used for the views V2 and V3 be
>> > brought
>> > in to memory for processing or will the filters applied on V1 would
>> > restrict
>> > the data on the other views as well due to the joins used between the
>> > three
>> > views to create V123.
>> >
>> > Basically, when you have nested views and if the data filter is used
>> > only on
>> > one of the view used in the nested view, what happens to other views
>> > used in
>> > the nested view.
>> >
>> > Appreciate your help.
>> >
>> > Thanks,
>> > Latha
>> >
>> >