Tablespace Data Dictionary Views

View	Description
V$TABLESPACE	Name and number of all tablespaces from the control file.
V$ENCRYPTED_TABLESPACES	Name and encryption algorithm of all encrypted tablespaces.
DBA_TABLESPACES, USER_TABLESPACES	Descriptions of all (or user accessible) tablespaces.
DBA_TABLESPACE_GROUPS	Displays the tablespace groups and the tablespaces that belong to them.
DBA_SEGMENTS, USER_SEGMENTS	Information about segments within all (or user accessible) tablespaces.
DBA_EXTENTS, USER_EXTENTS	Information about data extents within all (or user accessible) tablespaces.
DBA_FREE_SPACE, USER_FREE_SPACE	Information about free extents within all (or user accessible) tablespaces.
DBA_TEMP_FREE_SPACE	Displays the total allocated and free space in each temporary tablespace.
V$DATAFILE	Information about all datafiles, including tablespace number of owning tablespace.
V$TEMPFILE	Information about all tempfiles, including tablespace number of owning tablespace.
DBA_DATA_FILES	Shows files (datafiles) belonging to tablespaces.
DBA_TEMP_FILES	Shows files (tempfiles) belonging to temporary tablespaces.
V$TEMP_EXTENT_MAP	Information for all extents in all locally managed temporary tablespaces.
V$TEMP_EXTENT_POOL	For locally managed temporary tablespaces: the state of temporary space cached and used for by each instance.
V$TEMP_SPACE_HEADER	Shows space used/free for each tempfile.
DBA_USERS	Default and temporary tablespaces for all users.
DBA_TS_QUOTAS	Lists tablespace quotas for all users.
V$SORT_SEGMENT	Information about every sort segment in a given instance. The view is only updated when the tablespace is of the TEMPORARY type.
V$TEMPSEG_USAGE	Describes temporary (sort) segment usage by user for temporary or permanent tablespaces.