In data management and database analysis, a data domain refers to all the unique values which a data element may contain. The rule for determining the domain boundary may be as simple as a data type with enumerated list of values. Data management comprises all the disciplines related to managing data as a valuable resource. ... This article is about computing. ... In metadata, the term data element is an atomic unit of data that has: An identification such as a data element name A clear data element definition One or more representation terms Optional enumerated values Code (metadata) A list of synonyms to data elements in other metadata registries Synonym ring... In programming languages a data type defines a set of values and the allowable operations on those values[1]. For example, in the Java programming language, the int type represents the set of 32-bit integers ranging in value from -2,147,483,648 to 2,147,483,647, and... In mathematics and theoretical computer science, an enumeration of a set is a procedure for listing all members of the set in some definite sequence. ...

For example, a database table that has information about people, with one record per person, might have a "gender" column. This gender column might be declared as a string data type, and allowed to have one of two known code values: "M" for male, "F" for female -- and NULL for records where gender is unknown or not applicable (or arguably "U" for unknown as a sentinel value). The data domain for the gender column is : "M", "F". This article is about computing. ... In relational databases, SQL databases, and flat file databases, a table is a set of data elements (values) that is organized using a model of horizontal rows and vertical columns. ... Gender in common usage refers to the sexual distinction between male and female. ... For other uses, see Column (disambiguation). ... In programming languages a data type defines a set of values and the allowable operations on those values[1]. For example, in the Java programming language, the int type represents the set of 32-bit integers ranging in value from -2,147,483,648 to 2,147,483,647, and... In metadata, the representation term code refers to, and is used in the name of, data elements whose allowable values can be represented as enumerated lists. ... The Greek lowercase omega (ω) character is historically used by academics to represent Null in relational databases. ... In computer programming, a sentinel value (also referred to as a flag value, rogue value, or signal value) is a special value that is used to terminate a loop that processes structured (especially sequential) data. ...

In a normalized data model, the reference domain is typically specified in a reference table. Following the previous example, a Gender reference table would have exactly two records, one per allowed value -- excluding NULL. Reference tables are formally related to other tables in a database by the use of foreign keys. Database normalization, sometimes referred to as canonical synthesis, is a technique for designing relational database tables to minimize duplication of information and, in so doing, to safeguard the database against certain types of logical or structural problems, namely data anomalies. ... A data model is a model that describes how data are represented and used in an abstract way. ... Master Data Management (MDM), also known as Reference Data Management, is a discipline in Information Technology (IT) that focuses on the management of reference or master data that is shared by several disparate IT systems and groups. ... A reference table (or table of reference) may mean a set of references that an author may have cited or gained inspiration from whilst writing an article, similar to a bibliography. ... In the context of relational databases, a foreign key is a referential constraint between two tables[1]. The foreign key identifies a column or a set of columns in one (referencing) table that refers to a column or set of columns in another (referenced) table. ...

Less simple domain boundary rules, if database-enforced, may be implemented through a check constraint or, in more complex cases, in a database trigger. For example, a column requiring positive numeric values may have a check constraint declaring the values must be greater than zero. A check constraint (also known as table check constraint) is a condition that defines valid data when adding or updating an entry in a table of a relational database. ... A database trigger is procedural code that is automatically executed in response to certain events on a particular table in a database. ...

This definition combines the concepts of domain as an area over which control is exercised and the mathematical idea of a set of values of an independent variable for which a function is defined. See: domain (mathematics). In mathematics, a set can be thought of as any collection of distinct objects considered as a whole. ... In an experimental design, the independent variable (argument of a function, also called a predictor variable) is the variable that is manipulated or selected by the experimenter to determine its relationship to an observed phenomenon (the dependent variable). ... This article is about functions in mathematics. ... In mathematics, the domain of a function is the set of all input values to the function. ...

See also

• ISO/IEC 11179 Metadata standards
• Master Data Management
• Database
• Database table
• Data element
• Data management
• Data model
• Data modeling
• Foreign key
• Normalization
• Primary key
• Relational database
• Reference table