Cost of Parallel Evaluation of Operations in database management system free pdf
The time cost of parallel processing would then be 1/n of the time cost of sequential processing of the operation.
We must also account for the following costs:
• Startup costs for initiating the operation at multiple processors
• Skew in the distribution of work among the processors, with some processors getting a larger number of tuples than others
• Contention for resources—such as memory, disk, and the communication network—resulting in delays