Can I create index on Materialized view log

Question

Hello
The ADDM suggest me to create index on some fields of my materialized view log , I don't know does it cause any problem ? Is it safe ? have you done it before ?
thanks

Answer 1

Actually you can do it since materialized view log is in fact a table.
SQL> create table t(x int primary key);
Table created.
SQL> create materialized view log  on t;
Materialized view log created.
SQL> select segment_name, segment_type from user_segments;
SEGMENT_NAME
SEGMENT_TYPE
MLOG$_T
TABLE
T
TABLE
SYS_C004857
INDEX
SQL> desc mlog$_t;
Name                                      Null?    Type
X                                                  NUMBER
SNAPTIME$$                                         DATE
DMLTYPE$$                                          VARCHAR2(1)
OLD_NEW$$                                          VARCHAR2(1)
CHANGE_VECTOR$$                                    RAW(255)
SQL> create index i on mlog$_t(x);
Index created.However I don't know if this is really supported and makes sense.