Second order snapshot-log relations: supporting multi-directional database replication using asynchronous snapshot replication

Multi-directional asynchronous replication is a desired mechanism which allows updates to be performed locally at any site, and later propagated asynchronously to other sites. This paper proposes using second order snapshot-log relations as a mechanism for extending the use of single-directional asynchronous replication to multi-directional. The proposed mechanism is fully based on DBMS core tools and existing DBMS snapshot replication support, thus allowing a natural extension for systems that already support asynchronous snapshot replication. We have implemented and tested the proposed mecha-nism, showing results and terms of correctness.