SQL & PL/SQL

Hi All,

Getting the below error while trying to refresh the materialized view.

Error starting at line 1 in command:
BEGIN
dbms_mview.REFRESH ('MAT_V', 'COMPLETE');
END;
Error report:
ORA-01031: insufficient privileges
ORA-06512: at "SYS.DBMS_SNAPSHOT_UTL", line 350
ORA-06512: at "SYS.DBMS_SNAPSHOT_UTL", line 432
ORA-06512: at "SYS.DBMS_SNAPSHOT", line 2251
ORA-06512: at "SYS.DBMS_SNAPSHOT", line 2457
ORA-06512: at "SYS.DBMS_SNAPSHOT", line 2426
ORA-06512: at line 2
01031. 00000 -  "insufficient privileges"

I have given below rights to the user.

GRANT SELECT ANY DICTIONARY  TO vd_user;
GRANT ALTER ANY MATERIALIZED VIEW TO vd_user;
GRANT CREATE ANY MATERIALIZED VIEW TO vd_user;

Thanks,