Applications of Databases to Humanities and Social Sciences

Databases design

This presentation is not a complete course on databases design, but a first approach intended to specify the process and the concepts necessary to build coherent databases.

The approach and the vocabulary used here are intended for not specialists readers, without eluding the concepts essential to the design process: "Ce qui se conçoit bien s'énonce clairement, et les mots pour le dire arrivent aisément"... (Boileau)

The approach and the tool (see below) are not "toys" applications and allow you to build and use real relational databases.

------------------------------------
Comments, in green, are specially dedicated to "databases purist".
The design method, presented hereafter, is easy to use (by everybody) and operational. But easy doesn't mean simplistic. This method, like all relational databases design methods, relies on the works of Codd (1970) and Date (1975) and follows the recommandations of the ANSI-SPARK workshop group (1975). Only the needlessly verbose aspect of the "traditional" methods has been volontarily removed.
------------------------------------

IBEasy+, a software developed by the author allows you to:

1. Apply, pratically, the databases design stages presented in these pages
2. Design and use "easily" relational databases

The reader, most interested by the formal aspects can see, in these pages, the section "Normalization".

Fundamentals of Database

A database is a set of structured and not redundant information, whose organization is based on a data model.

The two keywords which intervene in the definition of a database are :
Structuring (by means of the data model) and no repetition (redundancy or minimal redundancy) of data.
To build a database consists in gathering data in "homogeneous" sets, ( entities, tables), each entity (table) being constituted of a finished number of elementary data, Attributes or Fields, repetition (redundancy) of attributes being minimal. The data model used in this presentation is the entity-relationship model.

Database management system (DBMS)

A DBMS is a software which plays the role of interface between the users and the Database.

A DBMS allows to describe, to handle and to question the data of a Database. A DBMS must manage all the problems connected to concurrent accesses, to protection and restoration of data, to control, integrity and security of data.

Database and spreadsheet

An error, frequently made by novice users, consists in confusing a database with a spreadsheet. The tables of a database are presented indeed in rows and columns, as in a spreadsheet, but the comparison stops there and differences between the two approaches are significant and numerous. The following table, summarizes the main differences between a database and a spreadsheet.

Databases design

The design of a Database, implies 3 fundamental stages:

1. Analyzing documents : construction of the data dictionary.
2. Structuring of the data dictionary : determination of entities and associations.
3. Linking entities together : the diagram of data. 
   
   

© Marc Grange, February 2001 | Last update: February 5, 2013