Page "Files-11" Paragraph 23

Every file has a version number, which defaults to 1 if no other versions of the same filename are present ( otherwise one higher than the greatest version ).

Every time a file is saved, rather than overwriting the existing version, a new file with the same name but an incremented version number is created.

Old versions can be deleted explicitly, with the < tt > DELETE </ tt > or the < tt > PURGE </ tt > command, or optionally, older versions of a file can be deleted automatically when the file's version limit is reached ( set by < tt > SET FILE / VERSION_LIMIT </ tt >).

Old versions are thus not overwritten, but are kept on disk and may be retrieved at any time.

The architectural limit on version numbers is 32767.

The versioning behavior is easily overridden if it is unwanted.

In particular, files which are directly updated, such as databases, do not create new versions unless explicitly programmed.