Outline of databases

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