serialisability

Serialisability is a property in database systems that ensures the concurrent execution of transactions produces the same result as if those transactions were executed one after another in some order. When multiple transactions access and modify shared data simultaneously, a serialisable schedule is one where the interleaving of operations from different transactions does not lead to an inconsistent database state. This consistency is crucial for maintaining data integrity.

There are different levels of serialisability. True serialisability, also known as conflict serialisability, guarantees that the outcome is identical to a sequential execution. Other forms, like view serialisability, offer weaker guarantees. Database management systems employ various concurrency control mechanisms, such as locking, timestamp ordering, or multi-version concurrency control, to enforce serialisability. These mechanisms aim to prevent conflicting operations from interfering with each other in a way that would violate serialisability. Achieving serialisability can sometimes come at the cost of reduced concurrency and performance, as the system may need to block or delay transactions to maintain the desired isolation level.