oracle redologs and logminer

• forcing log switches
  sql> alter system switch logfile;
  
  
• forcing checkpoints
  sql> alter system checkpoint;
  
  
• adding online redo log groups

sql> alter database add logfile [group 4]
sql> ('/disk3/log4a.rdo','/disk4/log4b.rdo') size 1m;


• adding online redo log members

sql> alter database add logfile member
sql> '/disk3/log1b.rdo' to group 1,
sql> '/disk4/log2b.rdo' to group 2;


• changes the name of the online redo logfile

sql> alter database rename file '/oracle/oradata/oradb/redo01.log'
sql> to '/oracle/oradata/redo01.log';


• drop online redo log groups

sql> alter database drop logfile group 3;


• drop online redo log members

sql> alter database drop logfile member '/oracle/oradata/redo01.log';


• clearing online redo log files

sql> alter database clear [unarchived] logfile '/oracle/log2a.rdo';


• using logminer analyzing redo logfiles

1. in the init.ora specify utl_file_dir = ' '
2. sql> execute dbms_logmnr_d.build('oradb.ora','/oracle/oradb/log');
3. sql> execute dbms_logmnr_add_logfile('/oracle/oradata/oradb/redo01.log',
   sql> dbms_logmnr.new);
4. sql> execute dbms_logmnr.add_logfile('/oracle/oradata/oradb/redo02.log',
   sql> dbms_logmnr.addfile);
5. sql> execute dbms_logmnr.start_logmnr(dictfilename=>'/oracle/oradb/log/oradb.ora');
6. sql> select * from v$logmnr_contents(v$logmnr_dictionary,v$logmnr_parameters
   sql> v$logmnr_logs);
7. sql> execute dbms_logmnr.end_logmnr;