3.3.12 Operands related to global buffers

35) pd_dbbuff_wait_interval = global-buffer-occupation-state-check-interval
[Figure]<unsigned integer>((0-2147483647))(milliseconds)
This operand applies only to a HiRDB/Parallel Server.
Specifies the interval at which the global buffer occupation state is to be checked. Specifying this operand changes the method of checking the global buffer occupation state.
When this operand is not specified
The following processing occurs:
[Figure]
When this operand is specified
The following processing occurs:
[Figure]
Specification guidelines
Specify this operand when all of the conditions listed below are satisfied. Performance may improve. Typically when this operand is used, a value of 1 is specified.
  • Global buffer lock-release wait has occurred. (You can check for this based on WAITL in the execution result of the pdbufls command.)
  • You want to improve performance even if the CPU usage rate must be increased.
If the CPU usage has become too high because 1 was specified in this operand, increase the value. If there is unused capacity in the CPU usage rate when 1 is specified in this operand, increase the pd_dbbuff_wait_spn_count operand value. Performance may improve.
36) pd_dbbuff_wait_spn_count = maximum-spin-loop-count-for-global-buffer-occupation-state-checking
[Figure]<unsigned integer>((0-2147483646))
This operand is applicable to a HiRDB/Parallel Server.
Specifies the maximum spin loop count in an interval loop that can occur during global buffer occupation state checking. For details, see the description of the pd_dbbuff_wait_interval operand.
Specification guidelines
Normally, there is no need to specify this operand. Specify this operand when you specify 1 in the pd_dbbuff_wait_interval operand.