Time for action – checking the redo transport service status

The following steps can be performed to check the redo transport service status:

1. The first query to be executed to be sure that the redo transport service is working properly will be the V$DATAGUARD_STATS view.

   SQL> SELECT NAME, VALUE, TIME_COMPUTED FROM V$DATAGUARD_STATS WHERE NAME='TRANSPORT LAG';
   
   NAME                   VALUE                TIME_COMPUTED
   ---------------------- -------------------- ----------------------
   transport lag          +00 00:00:00         08/27/2012 18:06:30

   The TIME_COMPUTED value has to be up-to-date. We can see that there is no redo transport lag in our logical standby configuration. We'll see a time value if there is a problem with the redo transport. Also, if there is an excessive redo generation on the primary database, this value may increase because the redo transport may not catch up with the redo generation. The lag must be zero again when the standby synchronized at the end.

2. By executing the...