How can distributed databases maintain consistency? This paper presents designs for several distributed concurrency controls, demonstrating their correct functioning in systems where databases are spread across multiple sites and applications "move" between sites. The paper explores the portion of the system that responds to the read and write requests of the application programs. The job maintains the global consistency of the distributed database while ensuring that the termination of the application programs is not prevented by phenomena such as deadlock. It investigates the implications of global consistency and discusses phenomena that can prevent application program termination, offering valuable insights for database designers and administrators. The paper assumes each individual site has its own local concurrency control which responds to requests at that site. These controls communicate with concurrency controls at other sites when an application program moves from site to site, terminates, or aborts. These concurrency control designs are essential for robust and reliable distributed database systems.
ACM Transactions on Database Systems publishes research on all aspects of database management systems. This paper aligns with the journal's scope by presenting new designs for distributed concurrency controls, a critical aspect of ensuring the consistency and reliability of distributed databases. The detailed analysis of concurrency control mechanisms and their implications for system performance and termination is highly relevant to the journal's readership.