re: SQL University: Parallelism Week - Part 3, Settings and Options
@DaveInternal deadlocks are resolved using a tempdb spill -- no reason to kill the query. In any case it does sound like some tuning would be ideal, but I agree that there is probably a bug there...
View Articlere: SQL University: Parallelism Week - Part 3, Settings and Options
You are correct, sir. The run-away query plan contained 10 Repartition Streams iterators and one Gather Streams iterator. We knew the query needed tuning, but the reason we opened the support case was...
View Articlere: SQL University: Parallelism Week - Part 3, Settings and Options
@DaveMy opinion is that your Microsoft support person is completely full of the excrement of a male bovine.But don't trust me on this without proof. Open up the query plan. How many Repartition Streams...
View Articlere: SQL University: Parallelism Week - Part 3, Settings and Options
Greetings and thank you for teaching the parallel pre-con in Chicago this year.>I have MAXDOP set to '4.' Why is my query spinning up 13 tasks?<We had a query spawning 17 threads on maxdop 2....
View Articlere: SQL University: Parallelism Week - Part 3, Settings and Options
@DanielYes, linked servers do indeed inhibit parallelism -- and a temp table is probably the best general case workaround. (I have another workaround, involving CLR, but you probably don't want to go...
View Articlere: SQL University: Parallelism Week - Part 3, Settings and Options
One more info: It was not about cost of serial plan vs parallel plan, I tried querytraceon 8649.GreetingsDaniel
View Articlere: SQL University: Parallelism Week - Part 3, Settings and Options
Hi Adam,first off all thanks for your Blog, I learned a lot here.Today, I was Troubleshooting a query that was not going parallel. I saw no inhibitors, then went back to check with the list. But...
View Articlere: SQL University: Parallelism Week - Part 3, Settings and Options
Hi AJ,2005, 2008, and 2008 R2. Most if not all of it probably applies to 2000 as well but to be honest I don't really remember. It's been six years since I've done anything in-depth with a 2000 instance.
View Articlere: SQL University: Parallelism Week - Part 3, Settings and Options
Adam,Does the information presented here apply to all versions of SQL evenly? As in 2000, 2005, 2008 and R2?We have all flavors in our shop. Fortunately most of mine are 08 and 08 R2, but I do have a...
View Articlere: SQL University: Parallelism Week - Part 3, Settings and Options
Michael, great point on RG. I had that on the list of things to discuss, but it fell into the 50% of topics I wasn't able to hit in just three blog posts. And since then I've thought of even more...
View Articlere: SQL University: Parallelism Week - Part 3, Settings and Options
Great series, thanks for posting it.Something to keep in mind is that you can use the Resource Governor to specify a MAXDOP for a Workload Group. Which will override the system default, and set a...
View Articlere: SQL University: Parallelism Week - Part 3, Settings and Options
Love it. Best SQLU week yet. At least for me. Learned a lot.
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