How to check standby redo log groups in Oracle Data Guard

Standby redo logs receive redo from the primary in Data Guard. This lists every standby redo log group, its current sequence, size in MB, and the physical member paths — the first thing to check when the standby is not applying redo.

SET LINES 100 PAGES 999
COL member FORMAT a70

SELECT st.group#,
       st.sequence#,
       CEIL(st.bytes / 1048576) AS mb,
       lf.member
FROM   v$standby_log st,
       v$logfile     lf
WHERE  st.group# = lf.group#;