Every one of us knows Bookmark Lookups in SQL Server. They are great, because you don’t need to care about your indexing strategy. They are bad, because with Bookmark Lookup you just introduce a bunch of other problems for your SQL Server installation. Almost every time when I’m on client side for consulting gigs, I have to fight with Bookmark Lookups, it’s like juggling hand grenades – you have to be very careful!

Because of this I’m speaking this Thursday evening at the Belgian SQL Server User Groups in Brussels about “The dangerous beauty of Bookmark Lookups“. Here’s the session abstract:

You know Bookmark Lookups in SQL Server, and you rely on them for your indexing strategy? But do you also know that they are the most dangerous thing in SQL Server, which can lead to massive performance losses that blows up your CPU and I/O resources? Join this session to get a basic understanding of Bookmark Lookup, and their associated performance problems. In detail you will learn about:

• The Tipping Point

• Parameter Sniffing Problems

• Bad Statistics

• Auto/Forced Parametrization

• Bookmark Lookup Deadlocks

If you are interested in seeing the other side of Bookmark Lookups, you are very welcome to attend the event, and you can register here: http://sqlug.be/blogs/official_sqlugbe_blog/archive/2013/04/08/the-dangerous-beauty-of-bookmark-lookups-april-18-with-klaus-aschenbrenner.aspx

Thanks for reading and see you soon in Brussels!

-Klaus