File Architecture (contd)
What if log file fails/lost ? : keep multiple copies of each log.
Loss of DB file : recover from last full backup and apply all redo logs from archives. All archives are numbered and applied in proper order.
Control Files : Keeps record of every other file. It has small size. It is very critical and hence multiple copies are stored. It contains filename, last checkpoint time, etc.
Initialize Parameters Files (init.ora) : Parameters for creating an instance. One or more for each DB. Different parameters for different sessions can be chosen.