This parameter specifies the maximum degree of intra-partition parallelism that is used for any SQL statement executing on this instance of the database manager. An SQL statement will not use more than this number of parallel operations within a partition when the statement is executed. For a partitioned database system, this parameter applies to the degree of database partition parallelism. The parallel_enable parameter must be set to "YES" to enable the database partition to use intra-partition parallelism.
The default value for this configuration parameter is -1. This value means that the system uses the degree of parallelism determined by the optimizer; otherwise, the user-specified value is used.
| Note: | The degree of parallelism for a SQL statement can be specified at statement compilation time using the CURRENT DEGREE special register or the DEGREE bind option. |
The maximum query degree of parallelism for an active application is specified using the SET RUNTIME DEGREE command. The actual runtime degree used is the lower of:
An exception regarding the determination of the actual query degree of parallelism occurs when creating an index. In this case, if parallel_enable is "YES" and the table is large enough to benefit from the use of multiple processors, then creating an index uses the number of online processors plus one. There is no effect from the other parameter, bind option, or special register mentioned above.
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