What is the components of DBMS and how they relate to each other?

Answer 1

DBMS architecturespecifies its components (including descriptions of their functions) and their interfaces. DBMS architecture is distinct from database architecture. The following are major DBMS components:

• DBMS external interfaces- They are the means to communicate with the DBMS (both ways, to and from the DBMS) to perform all the operations needed for the DBMS. These can be operations on a database, or operations to operate and manage the DBMS. For example:

- Direct database operations: defining data types, assigning security levels, updating data, querying the database, etc. - Operations related to DBMS operation and management: backup and restore, database recovery, security monitoring, database storage allocation and database layout configuration monitoring, performance monitoring and tuning, etc. An external interface can be either a user interface (e.g., typically for a database administrator), or an application programming interface (API) used for communication between an application program and the DBMS.

• Database language engines(or processors) - Most operations upon databases are performed through expression in Database languages (see above). Languages exist for data definition, data manipulation and queries (e.g., SQL), as well as for specifying various aspects of security, and more. Language expressions are fed into a DBMS through proper interfaces. A language engine processes the language expressions (by a compiler or language interpreter) to extract the intended database operations from the expression in a way that they can be executed by the DBMS.
• Query optimizer - Performs query optimization on every query to choose for it the most efficient query plan (a partial order (tree) of operations) to be executed to compute the query result.
• Database engine - Performs the received database operations on the database objects, typically at their higher-level representation.
• Storage engine - translates the operations to low-level operations on the storage bits. In some references the Storage engine is viewed as part of the database engine.
• Transactionengine - for correctness and reliability purposes most DBMS internal operations are performed encapsulated in transactions (see below). Transactions can also be specified externally to the DBMS to encapsulate a group of operations. The transaction engine tracks all the transactions and manages their execution according to the transaction rules (e.g., proper concurrency control, and proper commit or abort for each).
• DBMS management and operation component - Comprises many components that deal with all the DBMS management and operational aspects like performance monitoring and tuning, backup and restore, recovery from failure, security management and monitoring, database storage allocation and database storage layout monitoring, etc.
• Data definition subsystemhelps the user create and maintain the data dictionary and define the structure of the file in a database.
• Data manipulation subsystem helps the user to add, change, and delete information in a database and query it for valuable information. Software tools within the data manipulation subsystem are most often the primary interface between user and the information contained in a database. It allows the user to specify its logical information requirements.
• Application generation subsystem contains facilities to help users develop transaction-intensive applications. It usually requires that the user perform a detailed series of tasks to process a transaction. It facilitates easy-to-use data entry screens, programming languages, and interfaces.
• Data administration subsystem helps users manage the overall database environment by providing facilities for backup and recovery, security management, query optimization, concurrency control, and change management.

Answer 2

A DBMS (Database Management System) typically consists of three main components: the data, the database engine, and the database schema.

The data refers to the actual information that is stored within the database. The database engine is responsible for managing and organizing the data, performing tasks such as data retrieval, modification, and storage. The database schema defines the structure and organization of the database, including tables, fields, and relationships.

These components work together to enable efficient storage, retrieval, and manipulation of data within the database. The data is stored and organized by the database engine according to the specifications and rules defined in the database schema.