Hi,
are you agree with the followings :
Your database is running in the ARCHIVELOG mode. After an instance crash, you start up the database by issuing the STARTUP
command. Instance recovery is initiated by the SMON background process.
The information used for instance recovery will be derived from the control file.
The uncommitted changes are rolled back using information in the undo segments.
The committed and uncommitted changes stored in the online redo log are applied to the
affected data blocks.
Many thanks.