Components of physical database structure are given below.
- One or more data files.
- Two or more redo log files.
- One or more control files.
The physical database structure of an Oracle database consists of the following components:
- Datafiles: These are the actual physical files on disk where the data is stored. An Oracle database is comprised of one or more datafiles.
- Control files: Control files contain metadata about the database, such as the database name, names and locations of associated datafiles and redo log files, timestamps, and checkpoints.
- Redo log files: Redo log files record changes made to the database. They are crucial for recovering the database in the event of a failure.
- Tablespaces: Tablespaces are logical storage units within an Oracle database. They are made up of one or more datafiles and are used to group and manage related logical structures.
- Segments: A segment is a set of extents allocated for a specific data structure, such as a table or an index. Each table or index in a tablespace is made up of one or more segments.
- Extents: Extents are contiguous groups of data blocks allocated for a specific database object. They are the unit of space allocation in the Oracle database.
- Data blocks: Data blocks are the smallest units of data storage in an Oracle database. All database information is stored in data blocks.
Understanding these components is essential for managing and maintaining the physical structure of an Oracle database.