adLockReadOnly Default. Read-only—you cannot alter the data.
adLockPessimistic Pessimistic locking, record by record—the provider does what is necessary to ensure successful editing of the records, usually by locking records at the data source immediately upon editing.
adLockOptimistic Optimistic locking, record by record—the provider uses optimistic locking, locking records only when you call the Update method.
adLockBatchOptimistic Optimistic batch updates—required for batch update mode as opposed to immediate update mode.