- Also called:
- electronic database
- Key People:
- James Nicholas Gray
- Charles Bachman
- Michael Stonebraker
- Related Topics:
- data analysis
- record
- hypertext
- hypermedia
- file
- On the Web:
- National Alliance on Mental Illness - Psychosis (Oct. 16, 2026)
database
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What is a database in computer science?
In computer science, a database is a structured collection of data organized for rapid search and retrieval by a computer. It facilitates storing, retrieving, modifying, and deleting data alongside data-processing operations. A database management system (DBMS) extracts information from the database in response to queries.
Databases store data in files, broken down into records with fields, each containing information about an entity's attribute. Records are organized into tables showing relationships between fields. Users can rapidly search, rearrange, and group fields to retrieve or create reports using keywords and sorting commands. The power of a DBMS lies in its ability to define new relationships and use them to respond to queries.
Different types of DBMS include flat, hierarchical, network, relational, and object-oriented. SQL (Structured Query Language) is widely used in DBMS for relational databases.
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Why are databases useful for storing information?
Databases are useful for storing information because they are specially organized for rapid search and retrieval by a computer. They facilitate the storage, modification, and deletion of data, and a database management system (DBMS) extracts information from the database in response to queries.
Databases use files that are broken down into records, which consist of fields. Fields are the basic units of data storage, each containing information pertaining to one aspect of the entity described by the database. The power of a DBMS comes from its ability to define new relationships from the basic ones given by the tables and to use them to get responses to queries.
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What are some common types of databases?
Databases are structured to facilitate the storage, retrieval, modification, and deletion of data. Several different types of database management systems (DBMS) have been developed.
Common types of databases:
* Relational In this database, data is stored in tables, and links across tables are automatic. It is currently the most popular model for database management systems.
* Hierarchical Records are organized in a treelike structure.
* Network Creates multiple linkages between sets by placing links, or pointers, to one set of records in another.
* Object-oriented Stores and manipulates complex data structures, called objects, which are organized into hierarchical classes that may inherit properties from classes higher in the chain.
* NoSQL (non-relational) These databases don't need fixed tables. Many are document-oriented, storing voice, music, images, and video clips with text. XML databases are an important subset, widely used in Android app development.4 Britannica SourcesCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles. -
What is a database management system (DBMS)?
A database management system (DBMS) is a software system designed for the efficient storage, retrieval, and management of data within a database. It handles critical aspects such as security, accuracy, consistency, and response time, especially in networked database systems. DBMSs use algorithms to store, retrieve, update, and delete specific data items in the database. The most widely used type is the relational DBMS, which organizes data into tables that can be easily reorganized to facilitate different ways of accessing data. MySQL is a popular open-source relational DBMS.
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How do people get information out of a database?
People extract information from a database using a query language, which is a computer programming language designed for this purpose. These languages allow users to retrieve specific records or parts of records and perform calculations on them.
The most common method involves writing queries using a structured query language (SQL). SQL uses commands like "select", "find", "delete", and "print" to search databases. With a database management system (DBMS), users can define new relationships within the data to get responses to queries. The DBMS then extracts the needed information from the database.
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What is database normalization and why is it important?
Database normalization is organizing data to minimize redundancy and improve data integrity. It involves dividing databases into two or more tables and defining relationships between the tables. The goal is to isolate data so that changes to an attribute can be made in one table only and then propagate through the rest of the database using the defined relationships.
Normalization is important for several reasons:
- Minimizing redundancy: Reduces storage space and avoids inconsistencies.
- Improving data integrity: Ensures data is accurate and reliable.
- Simplifying data modification: Makes it easier to update and maintain the database.
- Enhancing query performance: Allows for faster and more efficient data retrieval.
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database, any collection of data, or information, that is specially organized for rapid search and retrieval by a computer. Databases are structured to facilitate the storage, retrieval, modification, and deletion of data in conjunction with various data-processing operations. A database management system (DBMS) extracts information from the database in response to queries.
A brief treatment of databases follows. For full treatment, see computer science: Information systems and databases; information processing.
A database is stored as a file or a set of files. The information in these files may be broken down into records, each of which consists of one or more fields. Fields are the basic units of data storage, and each field typically contains information pertaining to one aspect or attribute of the entity described by the database. Records are also organized into tables that include information about relationships between its various fields. Although database is applied loosely to any collection of information in computer files, a database in the strict sense provides cross-referencing capabilities. Using keywords and various sorting commands, users can rapidly search, rearrange, group, and select the fields in many records to retrieve or create reports on particular aggregates of data.
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Database records and files must be organized to allow retrieval of the information. Queries are the main way users retrieve database information. The power of a DBMS comes from its ability to define new relationships from the basic ones given by the tables and to use them to get responses to queries. Typically, the user provides a string of characters, and the computer searches the database for a corresponding sequence and provides the source materials in which those characters appear; a user can request, for example, all records in which the contents of the field for a person’s last name is the word Smith.
The many users of a large database must be able to manipulate the information within it quickly at any given time. Moreover, large business and other organizations tend to build up many independent files containing related and even overlapping data, and their data-processing activities often require the linking of data from several files. Several different types of DBMS have been developed to support these requirements: flat, hierarchical, network, relational, and object-oriented.
Early systems were arranged sequentially (i.e., alphabetically, numerically, or chronologically); the development of direct-access storage devices made possible random access to data via indexes. In flat databases, records are organized according to a simple list of entities; many simple databases for personal computers are flat in structure. The records in hierarchical databases are organized in a treelike structure, with each level of records branching off into a set of smaller categories. Unlike hierarchical databases, which provide single links between sets of records at different levels, network databases create multiple linkages between sets by placing links, or pointers, to one set of records in another; the speed and versatility of network databases have led to their wide use within businesses and in e-commerce. Relational databases are used where associations between files or records cannot be expressed by links; a simple flat list becomes one row of a table, or “relation,” and multiple relations can be mathematically associated to yield desired information. Various iterations of SQL (Structured Query Language) are widely employed in DBMS for relational databases. Object-oriented databases store and manipulate more complex data structures, called “objects,” which are organized into hierarchical classes that may inherit properties from classes higher in the chain; this database structure is the most flexible and adaptable.
The information in many databases consists of natural-language texts of documents; number-oriented databases primarily contain information such as statistics, tables, financial data, and raw scientific and technical data. Small databases can be maintained on personal-computer systems and used by individuals at home. These and larger databases have become increasingly important in business life, in part because they are now commonly designed to be integrated with other office software, including spreadsheet programs.
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Typical commercial database applications include airline reservations, production management functions, medical records in hospitals, and legal records of insurance companies. The largest databases are usually maintained by governmental agencies, business organizations, and universities. These databases may contain texts of such materials as abstracts, reports, legal statutes, wire services, newspapers and journals, encyclopaedias, and catalogs of various kinds. Reference databases contain bibliographies or indexes that serve as guides to the location of information in books, periodicals, and other published literature. Thousands of these publicly accessible databases now exist, covering topics ranging from law, medicine, and engineering to news and current events, games, classified advertisements, and instructional courses.
Increasingly, formerly separate databases are being combined electronically into larger collections known as data warehouses. Businesses and government agencies then employ “data mining” software to analyze multiple aspects of the data for various patterns. For example, a government agency might flag for human investigation a company or individual that purchased a suspicious quantity of certain equipment or materials, even though the purchases were spread around the country or through various subsidiaries.