IB Computer Science Topic A3.4.4: Features of Distributed Databases Key Definitions

The storing of copies of the same data at more than one site in a distributed database, which improves read performance and availability at the cost of keeping every copy up to date.

Deadlock occurs when processes are stuck waiting for resources held by each other.

A database whose data is stored across several physical sites, often on separate machines or in separate locations, while presenting itself to users and applications as a single logical database.

The property of a distributed database that hides how and where data is stored, so users and applications work with it as one database without knowing which site holds any given item.

The ability of a system to handle more data and more users by adding further nodes rather than by replacing existing hardware with something more powerful.

A protocol that makes a transaction atomic across several sites. A coordinator first asks every participating site to vote on whether it can commit, then tells every site to commit only if all votes were yes, and to abort otherwise.