A log input buffer for rollback is an area provided for each server in shared memory. This buffer differs from a log output buffer used for outputting system logs in that a single buffer sector is exclusively allocated to each transaction that rolls back. Therefore, depending on the sector count of a given log input buffer for rollback, the number of rollback processes that can be executed concurrently might be limited.

Tuning the sector count of a log input buffer for rollback can increase the number of rollback processes that can be executed concurrently. It might also shorten the rollback processing time.

Setting method

Specify 0 for the pd_log_rollback_buff_count operand. When 0 is specified, the sector count of a log input buffer for rollback is automatically determined by the system.

Note

Specifying the pd_log_rollback_buff_count operand might increase the sector count of a log input buffer for rollback, and might cause a memory shortage. In such a case, return the operand to its value before modification.