Parm Patram

These are the files (7) that make up the physical database:

1. Datafiles
   - a datafile can only be associated with one database
   - datafiles can be defined to ‘grow’
   - one or more datafiles form a logical unit of database storage called a ‘tablespace’.
2. Control Files
   - the control files store the locations of the datafiles and redo log files
   - also stores the database name and time of creation.
   - oracle can ‘multiplex’ the control files (keep many copies) to safeguard their contents.
3. Online Redo Log Files
   - ‘transaction log’ — keeps track of all changes to the data (kept in memory)
4. Archived Redo Log Files
   - once the online redo logs are written to disk they are now ‘archived’. The parameter ARCHIVELOG is how oracle will automatically archive the redo logs. You can store the archives on separate drives for protection.
5. Parameter Files
   - pfiles (parameter) and spfiles (server parameters) control the config options for the database and instance.
6. Alert and Trace Log Files
   - alert files = errors and warnings. Trace = used by background processes to dump diagnostic data.
7. Backup Files