DBA_TABLESPACE_USAGE_METRICS describes tablespace usage metrics for all types of tablespaces, including permanent, temporary, and undo tablespaces.

Column Datatype NULL Description
TABLESPACE_NAME VARCHAR2(30)   Tablespace name
USED_SPACE NUMBER   Total space consumed by the tablespace, in database blocks
TABLESPACE_SIZE NUMBER   Maximum size of the tablespace, in database blocks
USED_PERCENT NUMBER   Percentage of used space, as a function of the maximum possible tablespace size