Precisely Serializable Snapshot Isolation (PSSI)
Many popular database management systems provide Snapshot Isolation (SI) for concurrency control, either in addition to or in place of full serializability based on locking. Snapshot isolation was introduced in 1995, with noted anomalies that can lead to serializability violations. Full serializability was provided in 2008 and improved in 2009 by aborting transactions in dangerous structures, which had been shown in 2005 to be precursors to potential SI anomalies. This approach resulted in a run-time environment guaranteeing a serializable form of snapshot isolation (which the authors call SSI or ESSI) for arbitrary applications.