data dictionary in software engineering

“The data dictionary is an organized listing of all data elements that are pertinent to the system, with precise, rigorous definitions so that both user and system analyst will have a common understanding of inputs/outputs, and components of stores, and even intermediate calculations.”

A data dictionary is like any other dictionary, in that it defines each data element name. The data dictionary contains definitions for all data elements in the system being modelled, no more and no less.

In other words, a data dictionary is a repository (manual or computed-based) containing information about the various data objects appearing on each DFD.

Data dictionary is used to provide an organized approach for representing the characteristics of each data object and control item.

There are no standard formats for the data dictionary. The data store notation in a DFD shows the existence of one or more data items of stored data.

Generally, data dictionary includes such formats

• Name
• Alias
• Where-used/how-used
• Content description
• Supplementary information (type, restrictions or limitations)

Composite data may take the forms

• As a sequence of data items
• As a selection from among a set of data items
• As a repeated grouping of data items

Originally published at https://www.csmates.com.