SELECT
  group_id,                                -- GROUP_ID NUMBER
  group_name,                              -- GROUP_NAME VARCHAR2(64)
  metric_id,                               -- METRIC_ID NUMBER
  metric_name,                             -- METRIC_NAME VARCHAR2(64)
  metric_unit                              -- METRIC_UNIT VARCHAR2(64)
FROM
  gv$metricname
WHERE
  inst_id = USERENV('INSTANCE')