The final components of the Oracle architecture are the physical files where our information resided on disk.
Oracle has several types for data files, two of the five listed are described below.
- Database datafiles
- Control files
- Online redo logs
- Parameter files
- Other database related files
Database datafiles are physical files stored on disk and these files are used to store data on disk.
are only written to by the DBWR processes.
These database datafiles are associated with Oracle tablespaces
which are logical
containers for tables and indexes.
The Control File of the database is a binary file that contains a great deal of database information.
The control file contains the
- database name and
- data about the database log files.
Oracle cannot function without valid control files
Because the control file is so important, Oracle allows you to maintain duplicate copies of the control file.
When you have more than one control file, then you are said to be multiplexing
your control files. It is a good practice to put these multiple copies on different disks to protect the control file.