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Data Domain
In data management and database analysis, a data domain is the collection of values that a data element may contain. The rule for determining the domain boundary may be as simple as a data type with an enumerated list of values. For example, a database table that has information about people, with one record per person, might have a "marital status" column. This column might be declared as a string data type, and allowed to have one of two known code values: "M" for married, "S" for single, and NULL for records where marital status is unknown or not applicable. The data domain for the marital status column is: "M", "S". In a normalized data model, the reference domain is typically specified in a reference table. Following the previous example, a Marital Status 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. Simple domain boundary rules ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Data Management
Data management comprises all disciplines related to handling data as a valuable resource, it is the practice of managing an organization's data so it can be analyzed for decision making. Concept The concept of data management emerged alongside the evolution of computing technology. In the 1950s, as computers became more prevalent, organizations began to grapple with the challenge of organizing and storing data efficiently. Early methods relied on punch cards and manual sorting, which were labor-intensive and prone to errors. The introduction of database management systems in the 1970s marked a significant milestone, enabling structured storage and retrieval of data. By the 1980s, relational database models revolutionized data management, emphasizing the importance of data as an asset and fostering a data-centric mindset in business. This era also saw the rise of data governance practices, which prioritized the organization and regulation of data to ensure quality and complian ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reference Data
Reference data is data used to classify or categorize other data. Typically, they are static or slowly changing over time. Examples of reference data include: * Units of measurement * Country codes * Corporate codes * Fixed conversion rates e.g., weight, temperature, and length * Calendar structure and constraints Reference data sets are sometimes alternatively referred to as a "controlled vocabulary" or "lookup" data. Reference data differs from master data. While both provide context for business transactions, reference data is concerned with classification and categorisation, while master data is concerned with business entities. A further difference between reference data and master data is that a change to the reference data values may require an associated change in business process to support the change, while a change in master data will always be managed as part of existing business processes. For example, adding a new customer or sales product is part of the standard ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Master Data Management
Master data management (MDM) is a discipline in which business and information technology collaborate to ensure the uniformity, accuracy, stewardship, semantic consistency, and accountability of the enterprise's official shared master data assets. Reasons for master data management * Data consistency and accuracy: MDM ensures that the organization's critical data is Consistency (database systems), consistent and accurate across all systems, reducing discrepancies and errors caused by multiple, siloed copies of the same data. * Improved decision-making: By providing a single version of the truth, MDM aims to have business leaders make informed, Data-informed decision-making, data-driven decisions, and improve overall business performance. * Operational efficiency: With consistent and accurate data, operational processes such as reporting, inventory management, and customer service become more efficient. * Regulatory compliance: MDM tries to help organizations comply with industry ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Data Modeling
Data modeling in software engineering is the process of creating a data model for an information system by applying certain formal techniques. It may be applied as part of broader Model-driven engineering (MDE) concept. Overview Data modeling is a process used to define and analyze data requirements needed to support the business processes within the scope of corresponding information systems in organizations. Therefore, the process of data modeling involves professional data modelers working closely with business stakeholders, as well as potential users of the information system. There are three different types of data models produced while progressing from requirements to the actual database to be used for the information system.Simison, Graeme. C. & Witt, Graham. C. (2005). ''Data Modeling Essentials''. 3rd Edition. Morgan Kaufmann Publishers. The data requirements are initially recorded as a conceptual data model which is essentially a set of technology independent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Domain Of A Function
In mathematics, the domain of a function is the Set (mathematics), set of inputs accepted by the Function (mathematics), function. It is sometimes denoted by \operatorname(f) or \operatornamef, where is the function. In layman's terms, the domain of a function can generally be thought of as "what x can be". More precisely, given a function f\colon X\to Y, the domain of is . In modern mathematical language, the domain is part of the definition of a function rather than a property of it. In the special case that and are both sets of real numbers, the function can be graphed in the Cartesian coordinate system. In this case, the domain is represented on the -axis of the graph, as the projection of the graph of the function onto the -axis. For a function f\colon X\to Y, the set is called the ''codomain'': the set to which all outputs must belong. The set of specific outputs the function assigns to elements of is called its ''Range of a function, range'' or ''Image (mathematic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Function (mathematics)
In mathematics, a function from a set (mathematics), set to a set assigns to each element of exactly one element of .; the words ''map'', ''mapping'', ''transformation'', ''correspondence'', and ''operator'' are sometimes used synonymously. The set is called the Domain of a function, domain of the function and the set is called the codomain of the function. Functions were originally the idealization of how a varying quantity depends on another quantity. For example, the position of a planet is a ''function'' of time. History of the function concept, Historically, the concept was elaborated with the infinitesimal calculus at the end of the 17th century, and, until the 19th century, the functions that were considered were differentiable function, differentiable (that is, they had a high degree of regularity). The concept of a function was formalized at the end of the 19th century in terms of set theory, and this greatly increased the possible applications of the concept. A f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Independent Variable
A variable is considered dependent if it depends on (or is hypothesized to depend on) an independent variable. Dependent variables are studied under the supposition or demand that they depend, by some law or rule (e.g., by a mathematical function), on the values of other variables. Independent variables, on the other hand, are not seen as depending on any other variable in the scope of the experiment in question. Rather, they are controlled by the experimenter. In pure mathematics In mathematics, a function is a rule for taking an input (in the simplest case, a number or set of numbers)Carlson, Robert. A concrete introduction to real analysis. CRC Press, 2006. p.183 and providing an output (which may also be a number). A symbol that stands for an arbitrary input is called an independent variable, while a symbol that stands for an arbitrary output is called a dependent variable. The most common symbol for the input is , and the most common symbol for the output is ; the function ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Set (mathematics)
In mathematics, a set is a collection of different things; the things are '' elements'' or ''members'' of the set and are typically mathematical objects: numbers, symbols, points in space, lines, other geometric shapes, variables, or other sets. A set may be finite or infinite. There is a unique set with no elements, called the empty set; a set with a single element is a singleton. Sets are ubiquitous in modern mathematics. Indeed, set theory, more specifically Zermelo–Fraenkel set theory, has been the standard way to provide rigorous foundations for all branches of mathematics since the first half of the 20th century. Context Before the end of the 19th century, sets were not studied specifically, and were not clearly distinguished from sequences. Most mathematicians considered infinity as potentialmeaning that it is the result of an endless processand were reluctant to consider infinite sets, that is sets whose number of members is not a natural number. Specific ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Database Trigger
A database trigger is procedural code that is automatically executed in response to certain Event (computing), events on a particular Table (database), table or View (database), view in a database. The trigger is mostly used for maintaining the Database integrity, integrity of the information on the database. For example, when a new record (representing a new worker) is added to the employees table, new records should also be created in the tables of the taxes, vacations and salaries. Triggers can also be used to log historical data, for example to keep track of employees' previous salaries. Triggers in DBMS Below follows a series of descriptions of how some popular DBMS support triggers. Oracle In addition to triggers that fire (and execute PL/SQL code) when data is modified, Oracle Database, Oracle 10g supports triggers that fire when schema-level objects (that is, tables) are modified and when user logon or logoff events occur. Schema-level triggers * After Creation * Bef ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Check Constraint
A check constraint is a type of integrity constraint in SQL which specifies a requirement that must be met by each row in a database table. The constraint must be a predicate. It can refer to a single column, or multiple columns of the table. The result of the predicate can be either TRUE, FALSE, or UNKNOWN, depending on the presence of NULLs. If the predicate evaluates to UNKNOWN, then the constraint is not violated and the row can be inserted or updated in the table. This is contrary to predicates in WHERE clauses in SELECT or UPDATE statements. For example, in a table containing products, one could add a check constraint such that the price of a product and quantity of a product is a non-negative value: price >= 0 quantity >= 0 If these constraints were not in place, it would be possible to have a negative price (−$30) or quantity (−3 items). Check constraints are used to ensure the validity of data in a database and to provide data integrity. If they are used ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Foreign Key
A foreign key is a set of attributes in a table that refers to the primary key of another table, linking these two tables. In the context of relational databases, a foreign key is subject to an inclusion dependency constraint that the tuples consisting of the foreign key attributes in one relation, R, must also exist in some other (not necessarily distinct) relation, S; furthermore that those attributes must also be a candidate key in S. In other words, a foreign key is a set of attributes that a candidate key. For example, a table called TEAM may have an attribute, MEMBER_NAME, which is a foreign key referencing a candidate key, PERSON_NAME, in the PERSON table. Since MEMBER_NAME is a foreign key, any value existing as the name of a member in TEAM must also exist as a person's name in the PERSON table; in other words, every member of a TEAM is also a PERSON. Summary The table containing the foreign key is called the child table, and the table containing the candidate ke ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reference Table
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. It can also mean an information table that is used as a quick and easy reference for things that are difficult to remember such as comparing imperial with metric measurements. This kind of data is known as reference data. In the context of database design a reference table is a table into which an enumerated set of possible values of a certain field data type is divested. It is also called a domain table because it represents the domain for the columns that reference it. For example, in a relational database model of a warehouse the entity 'Item' may have a field called 'status' with a predefined set of values such as 'sold', 'reserved', 'out of stock'. In a purely designed database these values would be divested into an extra entity or Reference Table called 'status' in order to achieve database ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
