5. AccuRev Transactions

The AccuRev data repository is organized into a set of depots, each of which stores the complete revision history of a particular set of elements. Each depot has its own section of the database. Changes to a depot are structured as a series of transactions, each of which saves all the information involved in a particular change to the depot. Thus, the entire story of how a depot’s elements have evolved is contained in its transaction history.

Transactions are a well-established database technology, helping to guarantee that the database is always in a self-consistent state. But for AccuRev, transactions are not just a low-level mechanism for achieving database integrity. They play an essential role in organizing the user environment. Two aspects of AccuRev transactions make this possible: atomicity and immutability.