A naming service for a hierarchical namespace. The naming service includes a database system with a first table having first records. Each of the first records is for a hierarchical node and includes a node identifier and an ACL identifier to a set of access control rules applicable to the node. The database system includes a second table including second records, each record in the second records has one of the ACL identifiers from the first table correlated with a definition access control rules in the set of access control rules. The naming service includes an access control rule identifier generator configured to detect a set of access control rules for each node in the namespace and generate an a ACL identifier for each set of access control rules that can be stored in records in the first table and stored in records in the second table.