Question

I’m using the PagedList class in my web application that many of you might be familiar with if you have been doing anything with ASP.NET MVC and LINQ to SQL. It has been blogged about by Rob Conery, and a similar incarnation was included in things like Nerd Dinner, etc. It works great, but my DBA has raised concerns about potential future performance problems.

His issue is around the SELECT COUNT(*) that gets issued as a result of this line:

TotalCount = source.Count();

Any action that has paged data will fire off an additional query (like below) as a result of the IQueryable.Count() method call:

SELECT COUNT(*) AS [value] FROM [dbo].[Products] AS [t0] 

Is there a better way to handle this? I considered using the Count property of the PagedList class to get the item count, but realized that this won’t work because it’s only counting the number of items currently displayed (not the total count).

How much of a performance hit will this cause to my application when there’s a lot of data in the database?

Answer 1

iirc this stuff is a part of index stats and should be very efficient, you should ask your DBA to substatiate his concerns, rather than prematurely optimising.