A single sort allocates its own temporary segment in a temporary tablespace of the user issuing the statement and then returns the extents to the tablespaces.
Multiple sorts, however, can use sort segments in temporary tablespaces designated exclusively for sorts. These sort segments are allocated only once for the instance, and they are not returned after the sort, but remain available for other multiple sorts.
A temporary segment in a temporary table contains data for multiple statements of a single transaction or session. Oracle drops the temporary segment at the end of the transaction or session, returning the extents allocated for that segment to the associated tablespace.
