Indexes on Materialized Views

Hi,

We have implemented snapshot replication to make our internal data available to clients.

Do we need to create indexes on materialized views or oracle automatically used the indexes on the master tables. The materialized views are exactly sale as the master tables.. even their names.

For example

create materialized view company build immediate
as select * from company@dblink;

Please suggest.

Thanks
Ron

select index_name from user_indexes;