CURRENT DEGREE

The CURRENT DEGREE special register specifies the degree of I/O or Symmetric MultiProcessing (SMP) parallelism for the execution of queries, index creates, index rebuilds, index maintenance, and reorganizes. CURRENT DEGREE affects static and dynamic SQL statements. The data type of the register is CHAR(5). The valid values include:

1
No parallel processing is allowed.
2 through 32767
Specifies the degree of parallelism that will be used.
ANY
Specifies that the database manager can choose to use any number of tasks for either I/O or SMP parallel processing.

Use of parallel processing and the number of tasks used is determined based on the number of processors available in the system, this job's share of the amount of active memory available in the pool in which the job is run, and whether the expected elapsed time for the operation is limited by CPU processing or I/O resources. The database manager chooses an implementation that minimizes elapsed time based on the job's share of the memory in the pool.

NONE
No parallel processing is allowed.
MAX
The database manager can choose to use any number of tasks for either I/O or SMP parallel processing. MAX is similar to ANY except the database manager assumes that all active memory in the pool can be used.
IO
Any number of tasks can be used when the database manager chooses to use I/O parallel processing for queries. SMP is not allowed.

The value can be changed by invoking the SET CURRENT DEGREE statement. For details about this statement, see SET CURRENT DEGREE.

The initial value of CURRENT DEGREE is determined by the current degree in effect from the CHGQRYA CL command, PARALLEL_DEGREE parameter in the current query options file (QAQQINI), or the QQRYDEGREE system value.

Example

The following statement inhibits parallelism:

   SET CURRENT DEGREE  = '1'