States of Online Redo Log file

Online redo log file exists in any one of the following states:

1.current

2.active

3.inactive

4.unused

5.stale

 

If log writer is pointing then the state of the online redo log file is "current".

An online redo log file which is required for recovery exists in "active" state.

We cannot drop an active redo log file.

 

Note : We cannot resize an online redo log file.

 

An online redo log file which is not required for recovery either exists in inactive/unused/stale state.

 

An online redo log file with partial/incomplete data exists in stale state.