glossary
| access | The operation of seeking, reading, or writing data on a storage device. |
| access method | A technique used to transfer a physical record from or to a storage device. |
| alias | An alternative label used to refer to a data element. |
| application | A group of algorithms and data interlined to support an organizational requirement. |
| artifact | Information pertaining to the scope, analysis, design or construction of a system. |
| attribute | A fact about an entity or relationship, which can assume a value. |
| B tree | A binary storage structure and access method that maintains order in a database by continually dividing possible choices into two equal parts and reestablishing pointers to the respective sets but not allowing more than two levels of difference to exist concurrently. |
| before image | A snapshot of a record prior to update. |
| binary element | A data element that has either of two values -- true or false (one or zero). |
| binary search | A dichotomizing search with steps in which the sets of remaining items are partitioned into two equal parts. |
| bit | Short for binary digit. The lowest level of storage. A bit can assume two states - 1 (true) or 0 (false) |
| bit map | A specialized form of an index indicating the existence or nonexistence of a condition for a group of blocks or records. |
| buffer | An area of storage that holds data temporarily in main memory while data is being transmitted, received, read or written. |
| cache | A buffer usually built and maintained at the device level. |
| canonical model | A data model that represents the inherent structure of data without regard to either individual use or hardware or software implementation. |
| cardinality | A business rule specifying how many times (minimum and maximum) and entity can be related to another entity in a given relationship. |
| CASE | Computer-Aided Software Engineering. |
| checkpoint | An identified snapshot of a database or a point at which the transactions against the database have been frozen. |
| checkpoint/restart | A means of restarting a program at some point other than the beginning, for example, when a failure or interruption has occurred. |
| column | The physical implementation of a data element or attribute. |
| data | A recording of facts, concepts, or instructions on a storage medium for communication, retrieval, and processing by automatic means and presentation as information that is understandable by humans. |
| data administrator | The individual or organization responsible for the specification, acquisition, and maintenance of data management software and the design, validation, and security of files or databases. The DA is in charge of the data dictionary and data model. |
| data definition | The specification of the data entities, their attributes, and their relationships in a coherent database structure to create a schema. |
| data dictionary | A software tool for recording the definition of data, the relationship of on category of data to another, the attributes and keys of groups of data, and so forth. |
| data element | An attribute of an entity. |
| data model | The logical data structures, including operations and constraints provided by a database management system for effective database processing. |
| data set | A names collection of logically related data items, arranged in a prescribed manner, and described by control information to which the programming systems have access. |
| data structure | A logical relationship among data elements that is designed to support specific data manipulation functions. |
| data warehouse | A collection of integrated subject-oriented databases designed to support the decision support systems function, where each unit of data is relevant to some moment in time. |
| database administrator | The organizational function charged with the day-to-day monitoring and care of the databases. The DBA is responsible for the physical database design. |
| dataview | Any collection or representation of data which can be used to discover data element requirements in the domain of interest; for example, screen or report images, data flows on a data flow diagram, graphs, forms and file/record layouts. |
| design review | The quality assurance process in which all aspects of a system are reviewed publicly prior to construction of code. |
| dimensional model | A model, developed from the top down, used for depicting a business process through its relevant dimensions and facts. |
| domain | A pool of values from which one or more attributes draw their values. The domain specifies the legal values for an attribute; for example, date and amount |
| entity | A person, place, thing, concept, or event about which a business needs to keep information. |
| field | The physical implementation of an attribute. |
| file | A physical collection of one or more records or rows managed as a physical set by a database management system |
| foreign key | The primary key of one file or table which is implanted in another file or table to implement the relationships between them. Foreign keys are used to implement some types of relationships. Foreign keys do not exist in information models. |
| functional dependency | An association between a primary key and attribute; exists if at every moment in time, for one value of the key, one and only one value of the attribute exists. |
| index | The physical implementation of a primary key (unique index) or secondary key (non-unique or secondary index) maintained and used transparently by the DBMS. |
| information model | A model of the information requirements of a business or business area. An information model consists of a diagram and definitions of each entity, attribute and relationship. |
| logical data model | A model that represents the true structure of data, independent of software or hardware implementation constraints. |
| normalization | A process for structuring data to organize it into its most natural, stable, subject-oriented, shareable, and non-redundant form. |
| primary key | An attribute selected to act as the unique identifier for each occurrence of an entity or relationship. A primary key must be unique, stable, minimal and non-null under all conditions. |
| reference table | A table generated to implement a many-to-many relationship. |
| referential integrity | The requirement that the foreign key values of an instance of a child entity have corresponding values in a parent entity. |
| relationship | A business associate between one or more entities. |
| repeating group | A set of related attributes which occurs more than once with an entity or table. |
| row | A group of fields or columns related by a common identifier. |
| secondary key | An attribute designed as an alternate means of accessing data; this attribute is not necessarily unique, stable, minimal or non-null. |
| sub-type entity | An entity which is a sub-category of another entity (supertype). A subtype have specific attributes and/or relationships that it does not share with other subtypes of the same supertype entity. |
| super-type entity | An entity which is a higher-level category of another entity (subtype). |
| table | A physical collection of one or more records or rows, managed as a physical set by the DBMS. |
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