Optimizing updates

showplan messages provide information about whether an update is performed in direct mode or deferred mode. If a direct update is not possible, Adaptive Server updates the data row in deferred mode. There are times when the optimizer cannot know whether a direct update or a deferred update will be performed, so two showplan messages are provided:

These types of direct updates depend on information that is available only at runtime, since the page actually has to be fetched and examined to determine whether the row fits on the page.