Chapter 14. Concurrency Control
For the most part, today's DBMSs are intended as shared resources. 1
A single database may be supporting thousands of users at one time. We call this type of use concurrent use
. However, although many users are working with the same database, it does not mean that more than one user is (or should be) working with exactly the same data as another at precisely the same moment.
It is physically impossible for two users to read or write exactly the same bit on a disk at precisely the same time. Operating systems and hardware disk controllers work together to ensure that only one ...