Maheen

• Jul 9th, 2005

 

A segment is a set of extents that contains all the data for a specific logical storage structure within a tablespace. For example, for each table, Oracle allocates one or more extents to form that table's data segment, and for each index, Oracle allocates one or more extents to form its index segment. 
 
Oracle databases use four types of segments, which are described in the following sections: 
 
A single data segment in an Oracle database holds all of the data for one of the following: 
 
A table that is not partitioned or clustered  
A partition of a partitioned table  
A cluster of tables