Code:
sys@DSIM>select * from V$TEMP_EXTENT_POOL;

TABLESPACE_NAME                   FILE_ID EXTENTS_CACHED EXTENTS_USED BLOCKS_CACHED BLOCKS_USED BYTES_CACHED BYTES_USED RELATIVE_FNO
------------------------------ ---------- -------------- ------------ ------------- ----------- ------------ ---------- ------------
TEMP                                    1          15999           28        255984         448   2097020928    3670016            1