The number of synchronous reads/writes across all active databases in the instance. This value shows the number of database agents that are reading pages from disk to buffer pools, and writing pages from buffer pools to disk. These reads and writes are synchronous because they are performed as part of the processing of program instructions.
Note: In a multiple-partition database, information is presented for each active partition on the system. An All Nodes row keeps a running total for all partitions. In a single-partition database, only the All Nodes information is presented.