Tablespace consists of one or more data files. A data file belongs to only one tablespace. Segments, Extents, and Blocks • Segments exist within a tablespace • Segments are made up of a collection of extents • An extents is a collection of logically contiguous data blocks - Cannot span multiple data files • Data blocks are mapped to disk blocks SYSTEM and SYSAUX Tablespaces • The SYSTEM and SYSAUX tablespaces are mandatory tablespaces. • They are created at the time of database creation. • They must be online. • The SYSTEM tablespace is used for core functionality (for example, data dictionary tables). • The auxiliary SYSAUX tablespace is used for additional database components.
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