75 ways to demystify DB2 #68: Techtip : Under which conditions DB2 choose Parallelism value of 1 (as a default)?
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Checking "parallelism" is one of the key factor when it comes to the performance scenario lets say for database backup. The algorithms behind DB2s self-tuning strategy does not select parallelism = 1 by default. Instead, it is based on many parameters including the number of available CPUs, the number of backup target devices, whether compression or encryption is in use, and the number of tablespaces being processed.
However, there are only four possible reasons why parallelism of 1 would be selected when backing up multiple table spaces :