Newbie temporary tablespaces question...

Greetings,

We are a noew Oracle shop, and the guy who did the initial install took off for the summer. When I try to select from some new views, I get an error saying that tablespace MISC_DATA does not exist. Looking at the tables below, it seems that MISC_DATA is marked INVALID. How do I validate it? And doesn't it's size seem awfully large?

Any help is most appreciated...

Dean

From sys.dba-users

USERNAME                      USER_ID    PA      DEFAULT_TABLESPACE             TEMPORARY_TABLESPACE
----------------------------- ---------- -------- ---------------------------------------------------
SYS                                    0 x        SYSTEM                         MISC_DATA
SYSTEM                                 5 x        TOOLS                          MISC_DATA
SCOTT                                  8 x        TOOLS                          TEMP
AXIS                                   9 x        AXIS1                          AXIS1
BARBARA                               13 x        SYSTEM                         SYSTEM
                                      
From sys.dba_tablespace
TABLESPACE_NAME                INITIAL_EX NEXT_EXTEN MIN_EXTENT MAX_EXTENT PCT_INCREA STATUS
------------------------------ ---------- ---------- ---------- ---------- ---------- ---------
SYSTEM                              12288      12288          1        249          0 ONLINE
RBS                                204800     204800         10         50         50 INVALID
TEMP                               262144     262144          1        249          0 ONLINE
TOOLS                               20480      20480          1        249         50 ONLINE
USERS                               20480      20480          1        249         50 ONLINE
MISC_DATA                       167772160    5242880          2         50          0 INVALID
ADMIN                               12288      12288          1        100          0 ONLINE
AXIS1                               53248      53248          2         50          0 ONLINE
MISC_RBS                         20971520    6291456          2         50         50 INVALID
MISC_RBS2                        20971520    6291456          2         50         50 ONLINE