Patent attributes
Transactional database replication techniques are disclosed. The techniques can be realized in many ways, such as in a replicator module that can be instantiated at each site in a distributed system. The techniques support a variety of data storage technologies such as traditional durable transactional databases as well as in-memory data storage systems, and a variety of data types such as relational, flat file, XML, and object-oriented data. Guaranteed levels of distributed transactional data consistency for both reads and writes are enabled for database applications. The techniques also support the ability of applications distributed across a network to perform updates concurrently, and the ability to replicate many standard database systems without needing to modify their intrinsic behavior or needing them to be aware of the replicator, and the ability to tolerate network and process failures without any change to the data consistency guarantees provided to the applications.