Cursor and Lock Characteristics
While the characteristics of a cursor depend upon capabilities of the provider, the following advantages and disadvantages generally apply to the various types of cursors and locks.
Cursor or lock type | Advantages | Disadvantages |
---|---|---|
adOpenForwardOnly | - Low resource requirements | - Cannot scroll backward - No data concurrency |
adOpenStatic | - Scrollable | - No data concurrency |
adOpenKeyset | - Some data concurrency - Scrollable |
- Higher resource requirements - Not available in disconnected scenario |
adOpenDynamic | - High data concurrency - Scrollable |
- Highest resource requirements - Not available in disconnected scenario |
adLockReadOnly | - Low resource requirements - Highly scalable |
- Data not updatable through cursor |
adLockBatchOptimistic | - Batch updates - Allows disconnected scenarios - Other users able to access data |
- Data can be changed by multiple users at once |
adLockPessimistic | - Data cannot be changed by other users while locked | - Prevents other users from accessing data while locked |
adLockOptimistic | - Other users able to access data | - Data can be changed by multiple users at once |