The following is provided as an overview of and topical guide to databases:

Database – organized collection of data, today typically in digital form. The data are typically organized to model relevant aspects of reality (for example, the availability of rooms in hotels), in a way that supports processes requiring this information (for example, finding a hotel with vacancies).

What type of things are databases?

Databases can be described as all of the following:

• Information – sequence of symbols that can be interpreted as a message. Information can be recorded as signs, or transmitted as signals.
• Data – values of qualitative or quantitative variables, belonging to a set of items. Data in computing (or data processing) are often represented by a combination of items organized in rows and multiple variables organized in columns. Data are typically the results of measurements and can be visualised using graphs or images.
• Computer data – information in a form suitable for use with a computer. Data is often distinguished from programs. A program is a sequence of instructions that detail a task for the computer to perform. In this sense, data is everything in software that is not program code.

Types of databases

• Active database – includes an event driven architecture (often in the form of ECA rules) which can respond to conditions both inside and outside the database.
• Animation database – stores fragments of animations or human movements and which can be accessed, analyzed and queried to develop and assemble new animations.
• Back-end database – accessed by users indirectly through an external application rather than by application programming stored within the database itself or by low level manipulation of the data (e.g. through SQL commands).
• Bibliographic database – database of bibliographic records, an organized digital collection of references to published literature, including journal and newspaper articles, conference proceedings, reports, government and legal publications, patents, books, etc.
• Centralized database – database located and maintained in one location, unlike a distributed database.
• Cloud database – runs on a cloud computing platform, such as Amazon EC2, GoGrid and Rackspace.
• Collection database – collection catalog of a museum or archive implemented using a computerized database, in which the institution's objects or material are catalogued.
• Collective Optimization Database – open repository to enable sharing of benchmarks, data sets and optimization cases from the community, provide web services and Plug-in (computing)|plugins to analyze optimization data and predict program transformations or better hardware designs for multi-objective optimizations based on statistical and machine learning techniques provided there is enough information collected in the repository from multiple users.
• Configuration management database –
• Cooperative database – holds information on customers and their transactions.
• Correlation database – database management system (DBMS) that is data model independent and designed to efficiently handle unplanned, ad hoc queries in an analytical system environment.
• Current database – conventional database that stores data that is valid now.
• Directory – repository or database of information which is optimized for reading, under the assumption that data updates are very rare compared to data reads. Commonly, a directory supports search and browsing in addition to simple lookups.
• Distributed database – database in which storage devices are not all attached to a common CPU.
• Document-oriented database – computer program designed for storing, retrieving, and managing document-oriented, or Semi-structured model|semi structured data, information.
• EDA database – database specialized for the purpose of electronic design automation.
• Endgame tablebase – computerized database that contains precalculated exhaustive analysis of a chess endgame position.
• Food composition database (FCDB) – provides detailed information on the nutritional composition of foods.
• Full-text database – database that contains the complete text of books, dissertations, journals, magazines, newspapers or other kinds of textual documents. Also called a "complete-text database".
• Government database – collects personal information for various reasons (mass surveillance, Schengen Information System in the European Union, social security, statistics, etc.).
• Graph database – uses graph structures with nodes, edges, and properties to represent and store data.
• Knowledge base – special kind of database for knowledge management. A knowledge base provides a means for information to be collected, organised, shared, searched and utilised.
• Mobile database – can be connected to by a mobile computing device over a mobile network.
• Navigational database – database in which objects (or records) in it are found primarily by following references from other objects.
• Non-native speech database – speech database of non-native pronunciations of English.
• Online database – database accessible from a network, including from the Internet.
• Operational database – accessed by an Operational System to carry out regular operations of an organization.
• Parallel database – improves performance through parallelization of various operations, such as loading data, building indexes and evaluating queries.
• Probabilistic database – uncertain database in which the possible worlds have associated probabilities.
• Real-time database – processing system designed to handle workloads whose state is constantly changing (Buchmann).
• Relational database – collection of data items organized as a set of formally described tables from which data can be accessed easily.
• Spatial database – database that is optimized to store and query data that is related to objects in space, including points, lines and polygons.
• Temporal database – database with built-in time aspects, for example a temporal data model and a temporal version of Structured Query Language (SQL).
• Time series database – a time series is an associative array of numbers indexed by a datetime or a datetime range. These time series are often called profiles or curves, depending upon the market. A time series of stock prices might be called a price curve, or a time series of energy consumption might be called a load profile. Despite the disparate naming, the operations performed on them are sufficiently common as to demand special database treatment.
• Triplestore – purpose-built database for the storage and retrieval of triples, a triple being a data entity composed of subject-predicate-object, like "Bob is 35" or "Bob knows Fred".
• Very large database (VLDB) – contains an extremely high number of tuples (database rows), or occupies an extremely large physical filesystem storage space.
• Virtual private database (VPD) – masks data in a larger database so that security allows only the use of apparently private data.
• Vulnerability database – platform aimed at collecting, maintaining, and disseminating information about discovered vulnerabilities targeting real computer systems.
• XLDB – Stands for "eXtremely Large Data Base".
• XML database – data stored in XML format, where it can be queried, exported and serialized into the desired format.

History of databases

• History of databases –
• History of database management systems –:

Database use

• Database usage requirements –
• Database theory – encapsulates a broad range of topics related to the study and research of the theoretical realm of databases and database management systems.
• Database machine – or is a computer or special hardware that stores and retrieves data from a database. Also called a "back end processor"
• Database server – computer program that provides database services to other computer programs or computers, as defined by the client-server model.
• Database application – computer program whose primary purpose is entering and retrieving information from a computer-managed database.
  • Database management system (DBMS) – software package with computer programs that control the creation, maintenance, and use of a database.
• Database connection – facility in computer science that allows client software to communicate with database server software, whether on the same machine or not.
  • Datasource – name given to the connection set up to a database from a server. The name is commonly used when creating a query to the database. The Database Source Name (DSN) does not have to be the same as the filename for the database. For example, a database file named "friends.mdb" could be set up with a DSN of "school". Then DSN "school" would then be used to refer to the database when performing a query.
  • Data Source Name (DSN) – are data structures used to describe a connection to a data source. Sometimes known as a database source name though data sources are not limited to databases.
• Database administrator (DBA) – is a person responsible for the installation, configuration, upgrade, administration, monitoring and maintenance of physical databases.
• Lock –
• Comparison of database tools – (provides tables for comparing general and technical information for a number of available database administrator tools.)
• Database-centric architecture – software architectures in which databases play a crucial role. Also called "data-centric architecture".
• Intelligent database – was put forward as a system that manages information (rather than data) in a way that appears natural to users and which goes beyond simple record keeping.
• Two-phase locking (2PL) – is a concurrency control method that guarantees serializability.
• Locks with ordered sharing – comprises several variants of the Two phase locking (2PL) concurrency control protocol generated by changing the blocking semantics of locks upon conflicts.
• Load file – in the litigation community is commonly referred to as the file used to import data (coded, captured or extracted data from ESI processing) into a database; or the file used to link images.
• Database publishing – area of automated media production in which specialized techniques are used to generate paginated documents from source data residing in traditional databases.
• Halloween Problem – a phenomenon in databases in which an update operation causes a change in the physical location of a row, potentially allowing the row to be visited more than once during the operation.
• Log shipping – process of automating the backup of a database and transaction log files on a primary (production) database server, and then restoring them onto a standby server.

Database management systems

Database management system –

• Database model –
• Database normalization – organizing tables based on their attributes so that the data presented can avoid having redundancy and dependency.
• Database storage structures –
• Distributed database management system –
• Federated database system – type of meta-database management system (DBMS), which transparently maps multiple autonomous database systems into a single federated database.
• Referential integrity – .
• Relational algebra – offshoot of first-order logic (and of algebra of sets), deals with a set of finitary relations (see also relation (database)) that is closed under certain operators.
• Relational calculus – consists of two calculi, the tuple relational calculus and the domain relational calculus, that are part of the relational model for databases and provide a declarative way to specify database queries.
• Relational database – collection of data items organized as a set of formally described tables from which data can be accessed easily.
• Relational database management system (RDBMS) – database management system (DBMS) that is based on the relational model as introduced by E.
• Relational model – for database management is a database model based on first-order predicate logic, first formulated and proposed in 1969 by Edgar F.
• Object–relational database (ORD) – database management system (DBMS) similar to a relational database, but with an object-oriented database model: objects, classes and inheritance are directly supported in database schemas and in the query language. Also called object–relational database management system (ORDBMS).
• Transaction processing –

Database models

• Database model – theoretical foundation of a database and fundamentally determines in which manner data can be stored, organized, and manipulated in a database system. It thereby defines the infrastructure offered by a particular database system. The most popular example of a database model is the relational model.

Data warehouse

Data warehouse –

Database-related organizations

• Database
• Journal of Database Management

Database-related publications

• Ling Liu and Tamer M. Özsu (Eds.) (2009). "Encyclopedia of Database Systems, 4100 p. 60 illus. ISBN 978-0-387-49616-0. Table of Content available at http://refworks.springer.com/mrw/index.php?id=1217
• Beynon-Davies, P. (2004). Database Systems. 3rd Edition. Palgrave, Houndmills, Basingstoke.
• Connolly, Thomas and Carolyn Begg. Database Systems. New York: Harlow, 2002.
• Date, C. J. (2003). An Introduction to Database Systems, Fifth Edition. Addison Wesley. ISBN 0-201-51381-1.
• Gray, J. and Reuter, A. Transaction Processing: Concepts and Techniques, 1st edition, Morgan Kaufmann Publishers, 1992.
• Kroenke, David M. and David J. Auer. Database Concepts. 3rd ed. New York: Prentice, 2007.
• Lightstone, S.; Teorey, T.; Nadeau, T. (2007). Physical Database Design: the database professional's guide to exploiting indexes, views, storage, and more. Morgan Kaufmann Press. ISBN 978-0-12-369389-1.
• Teorey, T.; Lightstone, S. and Nadeau, T. Database Modeling & Design: Logical Design, 4th edition, Morgan Kaufmann Press, 2005. ISBN 0-12-685352-5

Database scholars

• Serge Abiteboul
• David Maier
• Ralph Kimball
• Kamran Parsaye
• C. J. Date
• Peter Chen

See also

• Outline of computing
  • Outline of software
• Databank
• Database model
• Database schema
• Record (database)
• Key (database)
• Internet research
• List of academic databases and search engines
• List of biodiversity databases
• List of Internet forums
• List of online databases

References

External links

• Databases at Curlie
• DB File extension – information about files with the DB extension