Concurrent Execution of a Transaction in DBMS pdf
Concurrent Execution of a Transaction in DBMS pdf Transaction: A transaction is defined as a logical unit of work that they required. It consists of more or more operations on a database that must be completed together so that the database remains in a consistent state. Suppose any type of information on the stock is stored in the database. The database stores two things i.e. sold list and quantity, This is one operation on the database. However, the quantity of the sold item n must also is subtracted from the items currently in stock. If both steps are not completed together, the database will be in an inconsistent state. The number of items in stock will be wrong if items are sold but not subtracted from items in stock. Commit and Rollback: A transaction is committed if it completes successfully and changes any type of data. if it fails and leaves the data unchanged, it is said that the transaction has been rolled back. Transaction properties (ACID properties)...