PARALLELISM is a close friend of DBA where you get to see it as a common occurence in the multi-processor server environment and during such performance issues you can also investigate whether a parallel plan is in use. For instance If a particular query is slow when it is using a parallel plan, you can try forcing a non-parallel plan by using the OPTION (MAXDOP 1) hint asper the documentation. CraigFreedman referring about parallel query execution and a discussion of query processing, query execution,...(
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