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3

Anyone ever see Cost Threshold for Parallelism being ignored? It is not being ignored. During the compilation process, the optimizer first considers a serial plan. If the estimated cost of that plan exceeds the Threshold, the optimizer goes on to look for a parallel plan. If the resulting parallel plan is costed below the best serial one, it will be ...


2

From the SQL Server query optimizer's point of view, there is not much to choose between the parallel and serial execution plans in this case. In general, the optimizer's cost model reduces the CPU cost (not the I/O cost) of operators in a parallel plan in proportion to the estimated degree of parallelism available. This CPU adjustment explains why the ...


2

I'm pretty sure that sp_BlitzCache will show you the cost of the actual plan used for your queries, whereas the server will considers a parallel plan when the initially estimated cost exceeds the threshold value. A noticable difference between estimated and actual query plan costs could happen if you have stale/bad statistics on your tables. If you've ...


-2

I, It doesn't ignore!. setting this parameter is only saying: The optimizer uses that cost threshold to figure out when it should start evaluating plans that can use multiple threads. for example : let say, your sql server got 4 threads, 3 of those threads are in use,soo only 1 left to use . if at this time you running your query, than it doesn't matter if ...


0

Look at http://stackoverflow.com/questions/11442191/parallelizing-a-numpy-vector-operation Essentially, you could do this in numpy relatively easily, with numexpr to take advantage of multi core. I haven't tried it yet, so YMMV.



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