-- list Redologs / Standby redologs groups and members
select GROUP#,THREAD#,MEMBERS,STATUS, BYTES/(1024*1024) Mb from v$log;
select GROUP#,THREAD#,STATUS, BYTES/(1024*1024) Mb from v$standby_log;

col MEMBER for a60
select * from v$logfile;

-- create standby redologs
select 'ALTER DATABASE ADD STANDBY LOGFILE THREAD '||thread#||' size '||bytes||';' from v$log;
select distinct 'ALTER DATABASE ADD STANDBY LOGFILE THREAD '||thread#||' size '||bytes||';' from v$log;

-- clear / drop standby redologs
select 'ALTER DATABASE CLEAR LOGFILE GROUP '||GROUP#||';' from v$standby_log;
select 'ALTER DATABASE DROP STANDBY LOGFILE GROUP '||GROUP#||';' from v$standby_log;