What to grant to user to use index of table while querying?

I want 开发者_如何学JAVAto know if oracle uses index when user queries data from table and that user has been granted just:

grant select on table to user

I want to know if it is needed some another grant to use index.

No, there is no requirement (or ability) to grant access to an index. If the user can access the table then their queries can use any available index.