N
snapshot isolation but monitors the read-write conflicts between
transactions to identify dangerous structures in the transaction
graph which indicate that a set of concurrent transactions might
produce an anomaly, and rolls back transactions to ensure that no
anomalies occur. It will produce some false positives (where a
transaction is rolled back even though there would not have been an
anomaly), but will never let an anomaly occur. In the two known
prototype implementations, performance for many workloads (even with
the need to restart transactions which are rolled back) is very close
to snapshot isolation and generally far better than an S2PL
implementation."