Cursors used to update or delete rows for a query that potentially references rows in a history table must be read-only.
DECLARE appcur CURSOR FOR SELECT * FROM policy_info
FOR SYSTEM_TIME AS OF '2011-02-28';
However, the following
statement results in an error because any cursor references to the
history rows are not read-only:DECLARE appcur CURSOR FOR SELECT * FROM policy_info
FOR SYSTEM_TIME AS OF '2011-02-28' FOR UPDATE;