What is the Scalar Operator in a SQL Query Plan?

What does it mean when you see the scalar operator in a query plan? How do you determine what expression lead to the operator? Join Grant Fritchey for a quick overview and you'll find query plans much less frustrating to read.

I'm currently working for FM Global, an industry leading engineering & insurance company, as a DBA. I've done development of large scale applications in languages such as VB, C# and Java. I've worked in SQL Server from the hoary days of 6.0. My nickname at work is the "The Scary DBA." I even have an official name plate with it. I wear it proudly. I was awarded a Microsoft MVP in April of '09.

Richard H. Lang II on 1/26/2009

Spending another 30 seconds on the video to tell us why this matters would have been nice.

mbourgon on 1/26/2009

I figured it'd be basic, but I didn't know about the "properties" trick.

Sara Karasik on 6/23/2009

Excellent presentation, (as usual) of something that I always wanted to know.

revanth on 6/30/2011

excellent , if possible can you explain how to convert hash joins to nested loops other than using query hints

D151BB6B9F on 6/30/2011

Too rushed.

G on 6/30/2011

Nice little tidbit, thanks. I think this is a good way to go at query plans which are a little overwhelming for the novice.

Deepak Kolapkar on 6/30/2011

Should explain more on execution plan for scalar operator

John Pertell on 7/1/2011

good clear explanation

Scott Taylor on 7/1/2011

please note that past tense of "to lead" is "led", not "lead"

Laxman on 7/4/2011

Good :)

Laxman on 7/4/2011

Good :)

Brynn Binnell on 7/4/2011

Great, but a bit more contextual info would have been useful. eg. what does scalar mean? why is it significant that the alias consumes extra resources? what should you do about it?

Steve Harris on 7/12/2011

In what circumstances would this be helpful?

Eric on 7/25/2011

Excellent explanation! I need all the execution plan help I can get.

John Kingery on 8/26/2011

Good. Is the scalar operator only the last item? Would like that answered.

Venky Subramaniam on 11/4/2011

Excellent...especially the definition and explanation of what a 'Compute scalar' actually implies and results in...

Maurice Ivory on 11/21/2011

This was good, I should have listen more and will redo this one.

6012FED587 on 11/22/2011

Too short