Transactions and concurrency
One of the principal purposes of databases is to support many simultaneous users. However, it is perfectly possible that different users may need to update the same data at the same time. The DBMS therefore needs ways to avoid conflicts in such situations. The problem is further complicated because it is sometimes necessary to update several different tables in the database as part of the same task.
This week we are looking at the main mechanisms that the DBMS users to maintain the integrity of the database contents in a multi-user environment. As always, there is much more detail on the subject than we can cover in this module. You can use the embedded links to find out more.