SQL/MP Reference Manual

HP NonStop SQL/MP Reference Manual—523352-013
X-7
=_SQL_CMP_CPUS_node DEFINE
=_SQL_CMP_CPUS_node DEFINE
The =_SQL_CMP_CPUS_node DEFINE is a system DEFINE that directs SQL to limit
processors used in a parallel query to a specified node.
_node
is the node associated with the processors to use for the query. _node is optional;
the default value is the current node.
Xhhhh
is the letter X (uppercase) followed by up to four hex characters. X has no purpose
other than to make the DEFINE syntactically correct. The hex character or
characters represent a unique configuration of available processors. For a sample
configuration and conversion from binary code to hex characters, see
Considerations in this entry.
Considerations—=_SQL_CMP_CPUS_node

Scope of =_SQL_CMP_CPUS_node
To specify available processors, add this DEFINE before you compile the query.
=_SQL_CMP_CPUS_node affects all parallel query plans compiled while the
DEFINE is in effect. To specify a different set of available processors for a new
parallel query, reset the DEFINE.
=_SQL_CMP_CPUS_node affects only the location of Executor Server Processes
(ESPs) for parallel plans. It does not affect the location of the master executor.
=_SQL_CMP_CPUS_node also has no effect upon:

Locations of sort processes used in the query

Locations of disk processes used in the query

Specifying the processor configuration—mapping binary code to hex code
=_SQL_CMP_CPUS_node syntax requires that you express a configuration of
processors to use for the parallel query as a string of up to four hex characters.
This example shows how to express the configuration as binary code, then how to
map the binary code to hex code. It assumes there are 16 processors on the
current node and that processors 0, 1, 2, 3, 8, 10, 12, and 15 are available.
First, assign each processor number a “1” if it is available or a “0” if it is not
available:
ADD DEFINE =_SQL_CMP_CPUS_node, CLASS MAP, FILE Xhhhh
CPU #: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Binary (ON/OFF) value: 1 1 1 1 0 0 0 0 1 0 1 0 1 0 0 1