Client datasets represent their data as an in-memory data packet. This packet is the value of the client dataset's Data property. By default, however, edits are not stored in the Data property. Instead the insertions, deletions, and modifications (made by users or programmatically) are stored in an internal change log, represented by the Delta property. Using a change log serves two purposes:

• The change log is required for applying updates to a database server or external provider component.
• The change log provides sophisticated support for undoing changes.

The LogChanges property lets you disable logging. When LogChanges is True, changes are recorded in the log. When LogChanges is False, changes are made directly to the Data property. You can disable the change log in file-based applications if you do not want the undo support. 

Edits in the change log remain there until they are removed by the application. Applications remove edits when

• Undoing changes
• Saving changes