How to create multiple indexes on the same column of a table?
Starting from oracle 12c, it is possible to create multiple indexes on the same column of a table. However, the index types should not be the same. For instance, one index can be B-tree index and the other one BITMAP index. In addition to that, the two indexes created for the same column should not be both visible at the same time.
Example:
SQL> CREATE INDEX imp_index on employees (emp_first_name);
SQL> CREATE BITMAP INDEX imp_bitindex on employees (emp_first_name) INVISIBLE;