Explain in detail the various functions performed by DBMS to ensure the integrity and consistency of the data in the database.

A DBMS performs several functions that guarantee the integrity and consistency of the data in the database. Most of these functions are transparent to the users and most can be achieved only through the use of a DBMS. Data Dictionary Management: The DBMS stores definitions of the data elements and their relationships (metadata) in a data dictionary. In turn, all programs that access the data in the database work through the DBMS. The DBMS uses the data dictionary to look up the required data component structures and relationships, thus relieving the programmer from having to code such complex relationships in each program. Data Storage Management: The DBMS creates and manages the complex structures required for data storage, thus relieving programmer from the difficult task of defining and programming the physical data characteristics. A modern DBMS provides storage not only for the data, but also for related data entry forms or screen definitions, report definitions, data validation rules, procedural code, structures to handle video and picture formats, etc. Data Transformation and Presentation: The DBMS transforms entered data to conform to required data structures. The DBMS formats the physically retrieved data to make it conform to the user's logical expectations. Security Management: The DBMS creates a security system that enforces user security and data privacy. Security rules determine which users can access the database which data items each user can access and which data operations (read, add, delete or modify) the user can perform. Multi-user Access Control: To provide data integrity and data inconsistency, the DBMS uses sophisticated algorithms to ensure that multiple users can access the database concurrently without compromising the integrity of the database. Backup and Recovery Management: The DBMS provides backup and data recovery to ensure data safety and integrity. Recovery management deals with the recovery of the database after a failure such as a bad sector in the disk or a power failure. Such capability is critical to preserving the database's integrity. Data Integrity Management: The DBMS promotes and enforces integrity rules, thus minimizing data redundancy and maximizing data inconsistency. The data relationships stored in the data dictionary are used to enforce data integrity. Ensuring data integrity is especially important in transaction-oriented database systems. Database Access Languages and API: The DBMS provides data access through a query language. The DBMS also provides application programming interfaces (API) to procedural languages such as COBOL, C, Java, etc. In addition, the DBMS provides administrative utilities used by the DBA and the database designer to create, implement, monitor and maintain the database. Database Communication Interface: Current generation DBMSs accept end-user requests via multiple, different network environments. For example, the DBMS might provide access to the database via the Internet through the use of Web browsers such as Internet Explorer, Firefox.