V$SORT_SEGMENT is only populated for temporary
tablespaces.
V$TEMPSEG_USAGE
From the perspective of users requesting temporary segments, the view V$TEMPSEG_USAGE
identifies the locations, types, and sizes of the temporary segments currently being requested.
Unlike V$SORT_SEGMENT, V$TEMPSEG_USAGE will contain information about temporary
segments in both temporary and permanent tablespaces. Later in this chapter, I??™ll introduce the
improved and simplified temporary tablespace management tools available in Oracle Database 11g.
Space Management Methodologies
In the following sections, we will consider various features of Oracle 11g to facilitate the efficient
use of disk space in the database. Locally managed tablespaces offer a variety of advantages to the
DBA, improving the performance of the objects within the tablespace, as well as easing administration
176 Oracle Database 11g DBA Handbook
of the tablespace??”fragmentation of a tablespace is a thing of the past. Another feature introduced
in Oracle9i, Oracle Managed Files, eases datafile maintenance by automatically removing files at
the operating system level when a tablespace or other database object is dropped. Bigfile
tablespaces, introduced in Oracle 10g, simplify datafile management because one and only one
datafile is associated with a bigfile tablespace. This moves the maintenance point up one level,
from the datafile to the tablespace. We??™ll also review a couple other features introduced in
Oracle9i??”undo tablespaces and multiple block sizes.
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