Integrity Maintenance | Database Management System

Integrity Maintenance | Database Management System

Integrity Maintenance : The various Security mechanisms discussed in the previous Section protects against accidental or intentional tampering of data whereas integrity Constraints ensure that any properly authorized access, alteration, deletion, or insertion of the data in the database does not change the consistency and validity of the data. This requires that there is a need for protection against incorrect database operations Database integrity ensures that data entered into the database is accurate, valid, and consistent. Any applicable integrity constraints and data validation rules must be satisfied before permitting a change to the database.

Three basic types of database integrity constraints are:

  • Entity integrity, allowing no two rows to have the same identity within a table.
  • Domain integrity, restricting data to predefined data types, e.g., dates.
  • Referential integrity, requiring the existence of a related row in another table, e.g., a student for a given student Roll No.

These integrity constraints ensure that either accidentally or intentionally the data in the database is not hampered. We have already discussed them in RDBMS chapter.

Database integrity involves the correctness of data and this correctness has to be preserved in case of concurrent operations, when there is error in the user’s operations or during running an application programs, and other failures in hardware and Software. The recovery Subsystem ensures that failures ofВ various types, which may cause the loss of some of the actions of one or more transactions, will not cause the database to become inconsistent.