Degradation in Performance When Autorefresh Interval Is Small

When a relatively short refresh interval, such as a few hundred milliseconds, is combined with a large number of entries in the log table or in the base table, a cache refresh operation does not complete before the next refresh operation is scheduled to begin. In this case, the entries in the log table can be un-marked when the current autorefresh cycle finishes.

Thus, the same rows can be refreshed from the base table to the cache group in the next autorefresh cycle, by which time the rows will be marked. Make sure that the time it for the refresh is greater than the refresh interval. Set the refresh interval to a value where redundant refreshes will not occur.