database key
41Database management system — Ein Datenbanksystem (DBS) ist ein System zur elektronischen Datenverwaltung. Die wesentliche Aufgabe eines DBS ist es, große Datenmengen effizient, widerspruchsfrei und dauerhaft zu speichern und benötigte Teilmengen in unterschiedlichen,… …
42key·word — /ˈkiːˌwɚd/ noun, pl words [count] : a word that is used to find information in a piece of writing, in a computer document, or on the Internet She typed the keywords “Medieval” and “medicine” into the search engine and pulled up a lot of results.… …
43Chemical database — A chemical database is a database specifically designed to store chemical information. This information is about chemical and crystal structures, spectra, reactions and syntheses, and thermophysical data. Contents 1 Types of chemical databases… …
44Surrogate key — A surrogate key in a database is a unique identifier for either an entity in the modeled world or an object in the database. The surrogate key is not derived from application data. Definition Two definitions of a surrogate appear in the… …
45Relational database — A visual diagram showing the relationship between the two tables, as indicated by the arrow A relational database matches data by using common characteristics found within the data set. The resulting groups of data uses the relational model (a… …
46Index (database) — A database index is a data structure that improves the speed of data retrieval operations on a database table at the cost of slower writes and increased storage space. Indexes can be created using one or more columns of a database table,… …
47Unique key — In relational database design, a unique key can uniquely identify each row in a table, and is closely related to the Superkey concept. A unique key comprises a single column or a set of columns. No two distinct rows in a table can have the same… …
48Microsoft Jet Database Engine — This article is about JET Red used in Microsoft Access. For the JET Blue ISAM implementation, see Extensible Storage Engine. The Microsoft Jet Database Engine is a database engine on which several Microsoft products have been built. A database… …
49Document-oriented database — A document oriented database is a computer program designed for storing, retrieving, and managing document oriented, or semi structured data, information. Document oriented databases are one of the main categories of so called NoSQL databases and …
50Domain/key normal form — (DKNF) is a normal form used in database normalization which requires that the database contains no constraints other than domain constraints and key constraints. A domain constraint specifies the permissible values for a given attribute, while a …
