V$SUBSCR_REGISTRATION_STATS displays information for diagnosability of notifications.
| Column | Datatype | Description | 
|---|---|---|
| REG_ID | NUMBER | Registration identifier | 
| NUM_NTFNS | NUMBER | Number of notifications | 
| NUM_GROUPING_NTFNS | NUMBER | Number of grouping notifications | 
| LAST_NTFN_START_TIME | TIMESTAMP(3) WITH TIME ZONE | Time when the last notification was started | 
| LAST_NTFN_SENT_TIME | TIMESTAMP(3) WITH TIME ZONE | Time when the last notification was sent | 
| TOTAL_EMON_LATENCY | NUMBER | Total EMON latency (time taken by the EMON slave to process notifications) | 
| EMON# | NUMBER | Active EMON slave serving the registration | 
| ALL_EMON_SERVERS | RAW(2000) | EMON slaves that served the registration | 
| TOTAL_PAYLOAD_BYTES_SENT | NUMBER | Total payload bytes sent | 
| NUM_RETRIES | NUMBER | Number of retries in sending notifications | 
| TOTAL_PLSQL_EXEC_TIME | NUMBER | Total PL/SQL callback execution time (relevant only for PL/SQL notifications) | 
| LAST_ERR | VARCHAR2(90) | Last error message | 
| LAST_ERR_TIME | TIMESTAMP(3) WITH TIME ZONE | Time of the last error | 
| LAST_UPDATE_TIME | TIMESTAMP(3) WITH TIME ZONE | Time of the last update |