Using the ONLY Keyword
If you use the UPDATE statement to update rows of a supertable,
rows from its subtables can also be updated. To update rows from the
supertable only, use the ONLY keyword prior to the table name, as
this example shows:
UPDATE ONLY(am_studies_super)
WHERE advisor = "johnson"
SET advisor = "camarillo";Note: If you use the UPDATE statement on a supertable without
the ONLY keyword and without a WHERE clause, all rows of the supertable
and its subtables are updated. You cannot use the ONLY keyword if
you plan to use the WHERE CURRENT OF clause to update the current
row of the active set of a cursor.