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Rob Farley

- Owner/Principal with LobsterPot Solutions (a MS Gold Partner consulting firm), Microsoft Certified Master, Microsoft MVP (SQL Server), and leader of the SQL User Group in Adelaide, Australia. Rob is a former director of PASS, and provides consulting and training courses around the world in SQL Server and BI topics.

Probe Residual when you have a Hash Match – a hidden cost in execution plans

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Published Tuesday, March 22, 2011 10:58 AM by Rob Farley



Rob Farley said:

I could go on all day about APPLY – it really is an incredible part of T-SQL. It helps solves problems

April 12, 2011 7:30 PM

Rob Farley said:

My guys are great! When PASS started accepting abstract submissions for their Summit (in October this

May 6, 2011 12:05 AM

Paul White: Page Free Space said:

You probably already know that it’s important to be aware of data types when writing queries, and that

July 18, 2011 9:06 PM

Chris Adkin said:

Presumably the use of filter indexes might be another option for solving this problem ?

November 27, 2012 3:41 AM

Rob Farley said:

Yes - but this post is more designed for highlighting the issue. I figure that solving it is a standard exercise in query tuning, once you see the impact of the Residuality.

November 27, 2012 3:45 AM

Dave said:

The bitly link don't work no more!! :(

March 9, 2014 9:20 PM

Dave said:

March 9, 2014 9:21 PM

Rob Farley said:

Hmm... As I wrote over on that post, it's working for me...

March 10, 2014 1:14 AM

jeff said:

"You’ll see here that for each Product we find, we look up the Subcategory name for it." Isn't that backwards? Hover over a "Nested Loops (Inner Join)" operator: "For each row in the top (outer) input, scan the bottom (inner) input, and output matching rows."

September 3, 2015 12:43 PM

Rob Farley said:

Hi Jeff - yes, that's a typo. 4.5 years this post has been up, and no one's mentioned that typo before. Maybe you're my only reader?

September 3, 2015 5:15 PM

jeff said:

Your only reader? I doubt it - your posts are really interesting! (Digging the stuff on LQS.) Maybe I'm the most OCD... :)

September 15, 2015 11:40 AM

Rob Farley said:

You like the stuff on LQS? Cool! You can have a raise!

September 15, 2015 5:12 PM

Jeroen said:

Nice post! Thanks!

February 11, 2016 4:59 AM

Harper said:

The post is so interesting. But how about the Nested Loop? Could we need using APPLY operator to solved the residual predicate?

August 22, 2016 11:32 PM

Lokesh said:

Thanks Rob for such great blogs.Very interesting and well described.

September 7, 2017 12:40 PM
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