We seem to have a misunderstanding over the definition of "optomistic locking".
To me, "optimistic" locking means the application doesn't do any locking when a record is read. All it does it to retain the timestamp of the record when it was read. When the application wants to write edited records back to the database, it does something like... BEGIN TRANSACTION re-read the record(s) to be written compare the timestamp with the timestamp when the record was read if they are different, abort the transaction, saying to the user something like "Can't update the database, someone else has changed it". write the edited record(s), updating the timestamp END TRANSACTION What you do when another user has changed a record is the tricky bit - you can throw away the user's edits, and start again, you can offer to overwrite the other user's updates (but be careful if there are related records), or you can be really clever and try to merge the two sets of changes. -- Nikki Locke, Trumphurst Ltd. PC & Unix consultancy & programming http://www.trumphurst.com/
