Time for action – checking the SQL Apply service status

The following steps can be performed to check the SQL Apply service status:

1. Use the following query on the logical standby database, to check the general SQL Apply status:

   SQL> SELECT * FROM V$LOGSTDBY_STATE;
   
      PRIMARY_DBID SESSION_ID REALTIME_APPLY  STATE
   --------------- ---------- --------------- ---------------
        1319333016          1 Y               APPLYING

   At the STATE column, we can see INITIALIZING, WAITING FOR DICTIONARY LOGS, LOADING DICTIONARY, WAITING ON GAP, APPLYING, and IDLE values, which describe the status of the SQL Apply clearly with their names.

2. The DBA_LOGSTDBY_LOG view, that we have queried in the Checking the Redo Transport Service Status action, will be very helpful to find the last applied archived log sequence and to check if there are archived log sequences that were received but not applied. Another view V$LOGSTDBY_PROCESS is helpful to control the status of the processes responsible for SQL Apply.

   SQL...