3.3.12 Operands related to global buffers
- 35) pd_dbbuff_wait_interval = global-buffer-occupation-state-check-interval
<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]](figure/zu020030.gif)
- When this operand is specified
- The following processing occurs:
![[Figure]](figure/zu020031.gif)
- 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
<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.