UNIFIED_AUDIT_SGA_QUEUE_SIZE can be useful when queued-write mode is used for unified auditing. In queued-write mode, audit records are first written to the SGA queue. When the SGA queue reaches a particular threshold, the audit records are flushed to the AUDSYS schema table. The SGA queue size should be tuned according to the audit data generation. If large numbers of audit records are generated very frequently, you can increase the size of SGA queue, so that frequent flushes of queue data can be prevented. Similarly, if fewer audit records are generated, a smaller size can be used for the SGA queue.