Do not call Destroy directly in an application. Usually destruction of datasets is handled automatically If an application creates its own instances of a dataset, however, the application should call Free, which checks that the dataset component is not nil before calling Destroy. 

Destroy calls its inherited destructor if necessary, frees the resources allocated for the BDE asynchronous callback, and sets the UpdateObject property for the dataset to nil. 

Create 

UpdateObject 

System::TObject::Free