SYS@PROD5> create tablespace test datafile '/u01/app/oracle/oradata/PROD5/test01.dbf' size 200m autoextend on;

Tablespace created.

SYS@PROD5> create user test identified by test default tablespace test;

User created.

SYS@PROD5> grant dba to test;

Grant succeeded.

SYS@PROD5> conn test/test
Connected.
TEST@PROD5> 
TEST@PROD5> create table t(x number, y number, z number);

Table created.

TEST@PROD5> insert into t values(1,1,1);

1 row created.

TEST@PROD5> insert into t values(2,2,2);

1 row created.

TEST@PROD5> insert into t values(3,3,3);

1 row created.

TEST@PROD5> commit; 

Commit complete.

TEST@PROD5> select * from t;

X    Y       Z
---------- ---------- ----------
1    1       1
2    2       2
3    3       3

TEST@PROD5> create materialized view log on t with sequence, rowid(x,y,z) including new values;

Materialized view log created.

TEST@PROD5> create materialized view m_t build immediate refresh fast on commit
  2  enable query rewrite as select x,y,z from t group by x,y,z;

Materialized view created.

TEST@PROD5> select segment_name,segment_type,tablespace_name from user_segments;

SEGMENT_NAME SEGMENT_TYPE    TABLESPACE_NAME
-------------------------------------------------------------------------------------------------------------------------------- ------------------ ------------------------------
I_MLOG$_T INDEX    TEST
I_SNAP$_M_T INDEX    TEST
MLOG$_T TABLE    TEST
M_T TABLE    TEST
T TABLE    TEST

TEST@PROD5> 
TEST@PROD5> col SEGMENT_NAME for a20
TEST@PROD5> /

SEGMENT_NAME     SEGMENT_TYPE TABLESPACE_NAME
-------------------- ------------------ ------------------------------
I_MLOG$_T     INDEX TEST
I_SNAP$_M_T     INDEX TEST
MLOG$_T     TABLE TEST
M_T     TABLE TEST
T     TABLE TEST

TEST@PROD5> drop tablespace test including contents and datafiles;
drop tablespace test including contents and datafiles
*
ERROR at line 1:
ORA-23515: materialized views and/or their indices exist in the tablespace

TEST@PROD5> drop materialized view m_t;

Materialized view dropped.

TEST@PROD5> select segment_name,segment_type,tablespace_name from user_segments;

SEGMENT_NAME     SEGMENT_TYPE TABLESPACE_NAME
-------------------- ------------------ ------------------------------
I_MLOG$_T     INDEX TEST
MLOG$_T     TABLE TEST
T     TABLE TEST

TEST@PROD5> drop tablespace test including contents and datafiles;

Tablespace dropped.