Standby DB only use 2 of 5 of standby redolog groups

Hi,

DB only use 2 of 5 of standby redolog groups

 

Only group name 15 and 16 are used:

 

select group#, thread#, sequence#, used, archived, status, first_change#, first_time from v$standby_log order by 1,2,3,4;

 

  GROUP# THREAD# SEQUENCE# USED ARCHIVED STATUS FIRST_CHANGE# FIRST_TIME

---------- ---------- ---------- ---------- ------------ ---------------------------------------- ------------- ------------------

  15 1 14052 438902272 YES ACTIVE 8.2675E+12 23-MAR-17

  16 1 0 0 NO UNASSIGNED <----- the next loop use it

  17 1 0 0 NO UNASSIGNED <----- never used

  18 1 0 0 YES UNASSIGNED <----- never used

  19 1 0 0 YES UNASSIGNED <----- never used

 

real time apply is used:

 

SQL> select DEST_ID,type,status,database_mode,recovery_mode,database_mode,srl from v$archive_dest_status where recovery_mode!='IDLE';