select * from v&log; --status of logfile groups
select * from v&logfile order by group#; --status of logfiles
select * from v&instance; --status of the archiver
alter system archive log start; --restart the archiver
alter system switch logfile; --switch online log
alter system set log_archive_max_processes=4;
--Add logfile group
alter database add logfile group 4
('&logfilename1',
'&logfilename2') size 64M;
--Drop logfile group and all members in it
alter database drop logfile group &N;
--Add logfile member
alter database add logfile member '&logfilename' reuse to group 4;
--Drop logfile member
alter database drop logfile member '&logfilename';
--Checking archivelog mode
select dbid, name, resetlogs_time, log_mode from v&database;
alter system archive log start; -- restarts the archiver
select * from v&archive_dest; -- archiver destinations
--Altering destination
alter system set log_archive_dest_1='location=&path';
alter system set log_archive_dest_state_1='enable';
--Archived log info from the control file
select * from v&archived_log;
--The sequence# of last backed up log
select thread#, max(sequence#) from v&archived_log
where BACKUP_COUNT>0 group by thread#;
--Redo size (MB) per day, last 30 days
select trunc(first_time) arc_date, sum(blocks * block_size)/1048576 arc_size
from v&archived_log
where first_time >= (trunc(sysdate)-30)
group by trunc(first_time);