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Summary of parallel init.oa parameters

Parameter Name	Default Value	Explanation
PARALLEL_ADAPTIVE_MULTI_USER	TRUE	Throttles DOP of a statement based on concurrent work load. Can lead to non-deterministic response times
PARALLEL_AUTOMATIC_TUNING	FALSE	Deprecated, retained for backward compatibility only
PARALLEL_DEGREE_LIMIT	CPU	Controls MAX DOP used with Auto DOP. CPU means DEFAULT DOP
PARALLEL_EXECUTION_MESSAGE_SIZE	16KB	Size of the buffers used by the parallel server processes to communicate with each other and the QC
PARALLEL_FORCE_LOCAL	FALSE	In a RAC environment controls if parallel server process will be limited to the node the statement is issued on or not
PARALLEL_INSTANCE_GROUP	N/A	Used in conjunction with INSTANCE_GROUPS parameter, it restrict parallel query operations to a limited number of instances
PARALLEL_IO_CAP_ENABLED	FALSE	Deprecated, retained for backward compatibility only
PARALLEL_MIN_PERCENT	0	Minimum percentage of the requested number of parallel execution processes required for parallel execution
PARALLEL_MIN_TIME_THRESHOLD	AUTO	Minimum execution time time a statement should have before AUTO DOP kicks in. Default 10 seconds.
PARALLEL_SERVERS_TARGET	4X DEFAULT DOP	Number of parallel server processes allowed to run before statement queuing kicks in
PARALLEL_THREADS_PER_CPU	2	Number of parallel server processes a CPU can handle during parallel execution