SQL/MP Reference Manual

HP NonStop SQL/MP Reference Manual—523352-013
X-8
=_SQL_CMP_DOUBLE_SBB_OFF DEFINE
The processors in this example are shown in groups of four, because each hex
character represents four processors:
Using this binary-to-hex conversion chart, the first group of four processors-0, 1, 2,
and 3-with the binary code “1111” map to the single hex character “F.” Mapping
binary codes for the remaining three groups of processors yields the hex
characters “0,” “A,” and “9,” respectively. Therefore, the complete hex character
expression for this processor configuration is “F0A9.” The
=_SQL_CMP_CPUS_node syntax for this configuration is:
ADD DEFINE =_SQL_CMP_CPUS, CLASS MAP, FILE XU0A9;
For nodes with fewer than 16 processors, SQL assumes that the missing trailing
hex characters are zero.

Availability of processors at compile time
When you compile a parallel query, the compiler assigns ESPs to the processors
specified as available in =_SQL_CMP_CPUS_node. If a processor is unavailable
when you compile the query no ESP is assigned to that processor, even if you
specified the processor as available in this DEFINE. In this case, the executor
chooses a substitute processor for the stranded ESP. The substitute processor
does not have to be specified as available in =_SQL_CMP_CPUS_node.
=_SQL_CMP_DOUBLE_SBB_OFF DEFINE
=_SQL_CMP_DOUBLE_SBB_OFF is a system DEFINE that directs SQL not to use
file system double buffering.
filename
must be a legal Guardian file name but has no purpose except to make the ADD
DEFINE command syntactically correct.
Hex Binary Hex Binary
0 0000 8 1000
1 0001 9 1001
2 0010 A 1010
3 0011 B 1011
4 0100 C 1100
5 0101 D 1101
6 0110 E 1110
7 0111 F 1111
ADD DEFINE =_SQL_CMP_DOUBLE_SBB_OFF, CLASS MAP,
FILE filename