Data Dictionary

Synonyms

System catalog; Metadata repository

Definition

A data dictionary catalogs the definitions of data elements, data types, data flows and other conventions that are used in an information system. Data dictionaries have been widely adopted by both (i) the database community, where a dictionary typically describes database entities, schemas, permissions, etc.; and (ii) the software development community, where a dictionary typically describes flows of information through the system. In essence, a data dictionary is a virtual database of metadata about an information system itself. A data dictionary may also be referred to as a “system catalog.”

Key Points

Understanding and managing an information system – both from a design and from an implementation point-of-view – requires some documentation of the schema, capabilities, constraints, and other descriptive features of the system. This documentation is typically embodied by a data dictionary – that is, a repository of information...