Comments on: SQL SERVER – Using MAXDOP 1 for Single Processor Query – SQL in Sixty Seconds #008 – Video http://blog.sqlauthority.com/2012/03/23/sql-server-using-maxdop-1-for-single-processor-query-sql-in-sixty-seconds-008-video/ Personal Notes of Pinal Dave Wed, 22 May 2013 19:03:49 +0000 hourly 1 http://wordpress.com/ By: SQL SERVER – Weekly Series – Memory Lane – #021 | SQL Server Journey with SQL Authority http://blog.sqlauthority.com/2012/03/23/sql-server-using-maxdop-1-for-single-processor-query-sql-in-sixty-seconds-008-video/#comment-442571 Sat, 23 Mar 2013 01:31:49 +0000 http://blog.sqlauthority.com/?p=17921#comment-442571 [...] Using MAXDOP 1 for Single Processor Query – SQL in Sixty Seconds #008 – Video There are always special cases when it is about SQL Server. There are always few queries which gives optimal performance when they are executed on single processor and there are always queries which gives optimal performance when they are executed on multiple processors. [...]

]]> By: Don http://blog.sqlauthority.com/2012/03/23/sql-server-using-maxdop-1-for-single-processor-query-sql-in-sixty-seconds-008-video/#comment-268557 Tue, 27 Mar 2012 23:19:05 +0000 http://blog.sqlauthority.com/?p=17921#comment-268557 Short of testing every single query, how do we know when to use this?

]]> By: sqlindian http://blog.sqlauthority.com/2012/03/23/sql-server-using-maxdop-1-for-single-processor-query-sql-in-sixty-seconds-008-video/#comment-266905 Sat, 24 Mar 2012 00:16:35 +0000 http://blog.sqlauthority.com/?p=17921#comment-266905 Brilliant Stuff!

Did you engineer the demo by manipulating DOP parameters and statistics or this can be reproed with out of the box configurations?

What is the plan warning (those exclamation marks on SELECT) you have in both the plans?

I believe that if you fix the warning, the optimizer will not choose a parallel plan for this query.

I was not able to repro this in any of my test environments even with a reduced cost threshold for parallelism.

In general, a parallel plan will have a bigger cost than a serial plan ONLY when the sum of the cost of the individual parallelism related operators (Repartition streams, gather streams etc) is greater than the sum of CPU cost reduction achieved in other operators due to parallelism. And in such scenarios the Optmizer generally favors the serial plan.

Full credits to you for coming up with such a special scenario.

It’ll be great if you can attach the xml plans to this post for getting the full picture :)

]]> By: chetan http://blog.sqlauthority.com/2012/03/23/sql-server-using-maxdop-1-for-single-processor-query-sql-in-sixty-seconds-008-video/#comment-266691 Fri, 23 Mar 2012 14:19:37 +0000 http://blog.sqlauthority.com/?p=17921#comment-266691 Hi Pinal Dave Sir,

I am not commenting for the above reply.

I am commenting by over all about the site of you.

When ever we face issues on MSBI, if we search for solutions,
if your face / site comes before us then we are getting confident that we can have a solution.
This kind of confidence you build for the people who are indeed on MSBI.

Thanks,
Chetan

]]> By: Keyur Thakkar http://blog.sqlauthority.com/2012/03/23/sql-server-using-maxdop-1-for-single-processor-query-sql-in-sixty-seconds-008-video/#comment-266669 Fri, 23 Mar 2012 13:49:18 +0000 http://blog.sqlauthority.com/?p=17921#comment-266669 Hi, pinal,,
i was at lalit 1 & 2 for this session,, to be very true,, loved your sppech and topic,,you make the difference,,,
hope i will see u next year,,,

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