There are many different methods to kill SQL server performance and one of the most bullet proof methods is correleated subqueries. In this blog post I’ll try to explain what correlated subqueries are, why th…

Many times when we work with SQL Server based applications, we solve performance problems by adjusting parallellism settings to limit the genereration of parallell query plans. However, sometimes we need to do th…

The last week I posted a blog about auto update stats and this is a sequal to that blog post. I case you haven’t read it you should read it first.

If you tried the script last week, you noticed that  :

• the statistics d…

Recently while working on a TB size SQL Server database, I got the opportunity to verify something that I have suspected for some time, but not yet looked into properly. I am talking about how to optimize UPDATE STATIS…

I guess most of you don’t use Extended Stored Procedures any more since we now can and should use CLR integration instead.

CLR integration has been around since version 2005 so this is old news, but, as a matter o…

In the last couple of weeks I’ve been helping one of our clients with some performance issues in a stored procedure. Somedays it works well and somedays it doesn’t.

After some investigations I found two…

Did you ever think that it would be great to cache SQL Server database query results, and only go back to query the database when data has changed? Well, you can do that, using Query Notifications.

Query notifications…

If you consider to migrate your database into SQL Azure you need to know if your database is compatible. In SQL Azure Labs you find an experimental cloud service called SQL Azure compatibility Assessment.

To test you…