Reduced Delta Sample

This sample shows how to use Reduced Deltas to save bandwidth when applying changes to the server, where rows may contain potentially large but unchanged data. With Reduced Delta on, Data Abstract will only submit the changed field of a particular row to the server, rather than sending all fields with Reduced Delta off.

Examine the code

See the TClientForm.btUpdateClick event handler to see how the dataset is updated. Note how the Reduced Delta feature can be turned on or off according to the checkbox.

Getting started

• Run the Sample Server.
• Run the Reduced Delta Sample.
• Try to fill DataSet.
• Try to change some records.
• Apply changes to the server, using the Update button.
• Examine the server log to see the command used on the server side to apply changes (it will contain only changed fields).
• Turn off the Reduced Delta feature using the radio button.
• Change some records and apply the changes to the server again.
• Examine the server log to see that when the Reduced Delta feature is turned off, all table fields are considered as changed.
  In this case we have used much more network traffic from client to server than what is normally passed.