A tablespace is the Oracle way of referring to a database file. A tablespace is a file set up to contain tables and is the primary logical storage structure for Oracle databases. Logical storage means the tablespace itself cannot be seen in the file system of the database server. The tablespace relates database objects to particular data files. Data files are physically located in the file system of the server.
An Oracle tablespace keeps information about various aspects of tables, including:
- Data types of columns
- Maximum length of data that is permissible in columns
Various types of tablespaces can exist in Oracle. A quite limited description of a few of these are:
Permanent tablespaces, such as the SYSTEM tablespace
- This is where Oracle’s data dictionary resides. If this table space gets deleted, your database will be gone.
- The SYSTEM tablespace is created by Oracle at the time the database is created.
- The SYSTEM tablespace stores the various units that comprise Oracle programs, such as packages, procedures, functions, and triggers.
Temporary tablespaces
- These are used primary for sort operations.
- Cannot contain permanent objects.
Undo tablespaces
- Stores records of transaction data before it is committed to the database.
- By creating an Undo tablespace, a DBA can control how long to keep rollback data.
Filed under: Oracle, Programming, SQL, Software, Technology, pl/sql | Tagged: data files, database, Oracle, pl/sql, SQL, system, tablespaces
