Concurrency controls
The table shown below describes common approaches to concurrency control.
| Pessimistic or Optimistic? | Coarse grained or Fine grained? | |
|---|---|---|
| Locking | Pessimistic - locks on View/Edit. Optimistic - Blocks on save - not really a lock. | Coarse grained -- locks the entire record. Fine grained -- locks the active field(s). |
| Validation checks | Users may unknowingly overwrite changes with their own, but validity is assured. | |
| No control | The specification limits access to a single user per record at a time. |