As with most files, when you open a sequential file, the Data File Editor loads the file into memory. All changes to the file
are stored in memory while you work on it. The file is written to disk when you save or close the file.
Indexed and Relative Files
Because these files can be quite large, the Data File Editor does not load indexed or relative files into memory when opened.
Each time you move your cursor off of a modified record, the Data File Editor updates the record on disk. If you have
Update warning configuration option checked, you are prompted to confirm the changes.