o  To use the RMU Delete Optimizer_Statistics command for a
       database, you must have the RMU$ANALYZE privilege in the root
       file access control list (ACL) for the database or the OpenVMS
       SYSPRV or BYPASS privilege.

    o  Cardinality statistics are automatically maintained by
       Oracle Rdb. Physical storage and workload statistics are only
       collected when you issue an RMU Collect Optimizer_Statistics
       command. To get information about the usage of physical
       storage and workload statistics for a given query, define
       the RDMS$DEBUG_FLAGS logical name to be "O". For example:

       $ DEFINE RDMS$DEBUG_FLAGS "O"

       When you execute a query, if workload and physical statistics
       have been used in optimizing the query, you will see a line
       such as the following in the command output:

       ~O: Workload and Physical statistics used

    o  Oracle Corporation recommends that you execute an RMU Show
       Optimizer_Statistics command with the Output qualifier prior
       to executing an RMU Delete Optimizer_Statistics command. If
       you accidentally delete statistics, you can replace them
       by issuing an RMU Insert Optimizer_Statistics command and
       specifying the statistical values contained in the output
       file.