Three Definitions: Relational Database

Introduction

This assignment’s objective is the following:

• Appreciate the importance and role of definitions in technical writing
• Understand how audience and purpose indicate the need for definition
• Differentiate between the levels of details in definition
• Select the right level of detail according to the situation

 

To do this, we define a complex term within our discipline or profession to a non-technical audience in the following ways:

• Parenthetical definition
• Sentence definition
• Expanded definition

 

Situation and Audience

A software engineer explains to their manager how their customer’s data is stored in a computer.

 

Parenthetical definition

Relational databases (databases where data is stored in rows and columns) are a common type of database to organize and store data.

 

Sentence definition

Relational databases are a type of database built upon a relational model. This database is characterized by its relational database management system, and Structured Query Language for reading and writing data from the database.

 

Expanded Definition

The most common database type in the 1960s were hierarchical databases where data is organized in a family tree type structure, where for example an Animal contains a Mammal which contains a Dog which contains a Golden Retriever.

Most data don’t have a hierarchical structure so E.F. Codd developed relational databases in 1970 where data is stored in relations, and if a common attribute can be used to link relations of a relation structure exists.

 

Relation name: Customers

CustomerID	Name
1	John
2	Sarah

Figure 1: Example of a relation

We can imagine relational databases as a collection of spreadsheet files. Each spreadsheet contains the following:

1. table (relation)
2. rows (tuples)
3. columns (attributes).

Referring to Figure 1, imagine we have a spreadsheet file “Customers”, in this case, the relation is called <Customers>, a tuple is <CustomerID: 1, Name: John>, and attributes are <CustomerID, Name>.

 

References:

Burleson, D. (n.d.). The Hierarchical Database Model. Retrieved February 8, 2023, from http://www.dba-oracle.com/t_object_hierarchical_database.htm

Codd, E. F. (1970). “A Relational Model of Data for Large Shared Data Banks”. Communications of the ACM. 13 (6): 377–387.

Note: I created my own image for the 3rd reference (The Figure). According to APA rules, no citation is needed.