Two additional configuration parameters for parallel query processing are:
number of sort buffers – configures the maximum number of buffers that parallel sort operations can use from the data cache.
memory per worker process – establishes a pool of memory that all worker processes use for messaging during query processing. The default value, 1024 bytes per worker process, provides ample space in almost all cases, so this value should not need to be reset.
See “Worker process management” on page 220 in the book Performance and Tuning: Monitoring and Analyzing for Performance for information on monitoring and tuning this value.
