Query hints influence view selection. By specifying members from one or more dimensions, the administrator can indicate to Essbase what types of queries are likely to occur. For example, to optimize queries at the bottom level of time, the administrator can specify one member at the bottom level of time, such as January. This tells Essbase that any member at the bottom level of the time dimension is likely to be queried. If no member is specified for a dimension, it means that the queries are equally likely to include members at any level of that dimension.
Query-based view selection ignores query hints, and user-defined view selection overrides them if there is a conflict between the two.
To apply query hints:
“Query Hints” in the Oracle Essbase Database Administrator's Guide