I remember one of the most surprising changes in SQL Server 2000 2005 was how the graphical plans showed the use of a nonclustered index to seek, and the plan included something that looked like a JOIN to find rows in the base table.  Here’s an example. Although I used SQL Server 2008R2, the graphical plan will be pretty similar to what it ...

I got a couple of really great questions during my SSWUG Workshop this morning, as I was discussing seeks and scans, and since the answers to the two questions are very related, I decided to address both of them in more detail in this blog post. Most people think about a seek operation as retrieving just one or a few rows, and a scan as ...

If you look up Table Hints in Books Online, you’ll find the following statement: If a clustered index exists, INDEX(0) forces a clustered index scan and INDEX(1) forces a clustered index scan or seek. If no clustered index exists, INDEX(0) forces a table scan and INDEX(1) is interpreted as an error. The interesting thing there is ...

As I told you in April, I recorded two more seminars with Stephen Wynkoop, on aspects of Query Processing. The first one will be broadcast on June 30 and the second on August 27. In between, we'll broadcast my Index Internals seminar, on July 23.  Workshops can be replayed for up to a week after the broadcast, and you can even buy a DVD of ...