public HiveAuthenticationProvider getAuthenticator() {
    return authenticator;
  }
Get the database object
@param catName catalog name.  If null, the default will be pulled from the conf.  This
               means the caller does not have to check isCatNameSet()
@param dbName database name.
@return
@throws HiveException
ql/src/java/org/apache/hadoop/hive/ql/security/authorization/HiveAuthorizationProviderBase.java