| ADO 2.5 |  |
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 |
|
|
| 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
|
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