A note about
multi-user database access. Whenever an user packs a database, or changes the record structure (adding/modifying/deleting fields), a problem shapes up: other users accessing the same db could make disasters by writing incorrect information on the db itself. Examples:
How are these issues handled? MaxBase knows about these problems, and thus everytime someone makes a "significant" change to the db, an internal counter (token) is incremented. Everytime MaxBase accesses a server, it presents its version of the token before doing the transaction and/or is told what is the current token. Whenever a user tries to modify the information contained in the db with a non up-to-date token, the server refuses to do the transaction, and the MaxBase instance automatically updates information to be presented to the user, in accord with the new token (e.g. the fields will automatically change name/size/indexing in the running MaxBase instance). This is transparent both to the user and the developer (who uses RXDBClient and JRXDBClient). The bottom line is: you can't harm the database by having more than one person working on it at once. (Bugs apart, that is) |
Max Marsiglietti © 1997
Layout and artwork Andrea Resmini 1997