IT 216 - System Analysis and Design - Chapter 8 Data Dictionaries

Flashcards for IT 216 - System Analysis and Design, Chapter 8: Data Dictionaries

Data Dictionary

A reference work of data about data (metadata) that collects and coordinates data terms, confirming their meaning to different people in the organization.

Metadata

Data about data; descriptions of the contents, format, and structure of a database and the relationship between its elements.

Data Repository

A large collection of project information, including data flows, data stores, record structures, elements, entities, messages, procedural logic, use cases, screen and report designs, data relationships, project requirements, and project management information.

Data Flow Diagram

A diagram used to catalog data processes, flows, stores, structures, and elements, often used in conjunction with a data dictionary.

Data Flow

Movement of data in a system; described by ID, name, description, source, destination, type, data structure, volume/time, and comments.

Data Structure

A composition of smaller structures and elements, described using algebraic notation (equal sign, plus sign, braces, brackets, parentheses).

Equal Sign (=) in Algebraic Notation

Means 'is composed of.'

Plus Sign (+) in Algebraic Notation

Means 'and.'

Braces ({}) in Algebraic Notation

Mean repetitive elements.

Brackets ([]) in Algebraic Notation

Indicate an either/or situation (mutually exclusive).

Parentheses (()) in Algebraic Notation

Indicate an optional element.

Data Element

A basic unit of data with characteristics such as ID, name, aliases, description, base/derived status, length, data type, input/output formats, validation criteria, default value, and comments.

Base Element

A data element that is initially keyed into the system.

Derived Element

A data element created by a process, often through calculation or decision-making.

Discrete Data

Data with fixed values, verified by checking values within a program or searching a table of codes.

Continuous Data

Data with a smooth range of values, checked for being within defined limits or ranges.

Data Store

A repository of data entities being stored, described by ID, name, alias, description, file type, file format, record numbers, data set name, data structure, primary/secondary keys, and comments.

XML (Extensible Markup Language)

A universal data language used to exchange data between businesses, define data, sort, filter, and translate data; documents can be transformed into different output formats.

XML Attributes

An additional piece of data included within a tag that describes something about the XML element.

XML Document Type Definition (DTD)

Used to determine if the XML document content is valid by conforming to the order and type of data that must be present in the document.

XML Schema

A precise way to define the content of an XML document, including the number of times an element may occur and the type of data within elements.