Chapter 10, Problem 1RQ

Explanation of Solution

Explanation of the given statement:

The given statement is “A transaction is a logical unit of work”. The statement describes the meaning of transaction in single statement. A transaction is a sequence of process that must be entirely completed or aborted. Intermediate states are not acceptable in the process of transaction.

• In DBMS, transaction act as a unit of logical related commands in which all the steps must be fully completed. If any of the SQL (Structured Query Language) command fails, the entire transaction is rolled back to the original database.
• If the transaction is acceptable by the DBMS (Database Management Systems), the transaction changes the database from one consistent state to another. To avoid inconsistent state, the DBMS must accept all database operations of the transaction are completed before the database committed.
• Consider the below example:
  • The database “sales” requires a minimum of two database operations. One is creation of product and another one is payment.
  • If the first operation is completed, the database will be left in an inconsistent state and the entire database is canceled. The transaction is accepted when all two operations are completed in the database.