Parallel Join Reset Options :: SAS® Scalable Performance Data Server 5.3: User's Guide

PLLJOIN / NOPLLJOIN

The PLLJOIN / NOPLLJOIN option enables and disables the server Parallel Join facility.

execute(reset noplljoin)
  by sasspds ; /* disables Parallel Join */

CONCURRENCY=

The CONCURRENCY=<n> option sets the concurrency level that the server Parallel Join facility uses. The integer value n specifies the number of levels. In most cases, you should not change the default server concurrency setting, which is half of the available number of processors.

Your concurrency value should not exceed 2. A concurrency of 1 or 2 for parallel merge join still provides parallelism and has been shown to give optimal performance based on benchmark testing results. A concurrency of 1 means that two threads are working in parallel. A concurrency of 2 means that three threads are working in parallel.

execute(reset concurrency=2)
  by sasspds ; /* enables 2 concurrency levels */

PLLJMAGIC

The PLLJMAGIC option specifies how SPD server performs parallel joins.

execute(reset plljmagic=<100/200>)
  by sasspds ;

PLLJMAGIC=100

forces a parallel range join when the range index is available.

PLLJMAGIC=200

forces a parallel merge join.