Defining and executing aggregations requires Calculation (Administration Services) or Execute (MaxL) permission or higher. Dimension builds that clear database values require Write permission.
See these security-related topics:
About Essbase Native Security Mode in the Oracle Essbase Database Administrator's Guide
“Managing User/Group Permissions for Applications and Databases”
in the Oracle Essbase Administration Services Online Help
“Privileges and Roles” in the Oracle Essbase Technical Reference