Is Filtering with a LinqDataSource Suppose to Filter at SQL Server?

[Kevin Warnke]

I was basing my code off the "Performance 300,000 rowcount example".  I just assumed that by following that model that the filtering MUST be done at the SQL server level.  Is that not correct?

I created a similar grid with a LinqDataSource that uses a DataContext that is LinqToSql.

The paging seems to be done at the SQL server level but when I filter I don't see any additional "where" clause which tells me that SQL server is returning ALL the rows and then .NET/Linq/Telerik/SomeoneElse is doing the filtering.

Is that right?  Or do I not have something configured properly so that the LinqDataSource will cause the WHERE to show up at SQL Server?

Thanks,
Kevin

[Kevin Warnke]

Follow up:

After re-reviewing the SQL traces it is running SQL with the correct where and order by (filter/sort).

However, BEFORE it runs the "correct" one it's repeating the execution of the original query.  So it's basically running 2 queries even though it only needs to run the second.

Any ideas on timing here and why it's doing that?

Thanks,
Kevin

[Kevin Warnke]

Well another thread, another one I answer on my own LOL.

The problem was I had ViewState disabled for the grid.  Apparantly when the grid is disabled it automatically re-creates itself even though it's not needed.

Anyone know how to supress this?  Or get ViewState to only include the details needed (page #, etc.) versus all the data too?

Thanks,
Kevin

[Iana Tsolova]

Hello Kevin,

Indeed, your findings anout the grid bound to LinqDataSource control are right - the fileting, paging and sorting are done on the SQL Server as the LinqDataSource supports them.
 
Regarding your last question: When RadGrid ViewState is disabled, RadGrid is reboundon each postback as you already observed. I suggest that you find the below articles for more information on how to optimize RadGrid ViewState:

http://www.telerik.com/help/aspnet-ajax/grdviewstateoptimization.html
http://www.telerik.com/help/aspnet-ajax/grdsavinggridviewstateinsession.html

Best wishes,
Iana
the Telerik team