Request order linked list (ROLL): a concurrency control object for centralized and distributed database systems

A database concurrency control object called ROLL (request order linked list), which is a linked list of bit vectors, is introduced together with three simple operations available to transactions: POST, CHECK and RELEASE. POST is used to establish serialization order. CHECK is used to determine current resource availability. RELEASE is used to relinquish resources. ROLL is based on the serialization graph testing method, but no system scheduler module is involved. Using ROLL, waiting, restarting, deadlock and livelock are minimized and almost all operations can be invoked in parallel by individual transaction manager modules. The ROLL object, performance, problems and desirable extensions are discussed