Video: three SQL Server join operators in three minutes

In an attempt to try a different approach, here’s a three-minute video explanation of how the different physical join operators in SQL Server work and why you would choose one over the other.

More reading

I’ve written a few blog posts on join operators befores, so if this video wet your appetite, here’s some recommended reading:

I’d love to hear what you think of the short video format! Please leave feedback in the comments below or on Twitter.

Key Lookup without an output column?

Performance tuning the other day, I was stumped by a query plan I was looking at. Even though I had constructed a covering index, I was still getting a Key Lookup operator in my query plan. What I usually do when that happens is to check the operator’s properties to see what its output columns are, so I can include those columns in my covering index.

Here’s the interesting thing: there weren’t any output columns. What happened?

Continue reading

Selectively disable “Include actual execution plan”

The “include actual execution plan” feature in SQL Server Management Studio is an invaluable tool for performance tuning. It returns the actual execution plan used for each statement, including actual row counts, tempdb spills and a lot of other information you need to do performance tuning.

But sometimes you want to run a series of statements or procedures where you only want the execution plan for some of the statements. Here’s how:

Continue reading