Database Fundamentals: A Video Introduction

(gentle music)

Databases and database systems exist everywhere. Most of your day to day activities will involve or will invoke some interaction with the database. From recording deposits and withdrawals at the bank to recording inventory levels at a supermarket, lots of activities involve someone or some computer programme accessing a database. The word database is commonly used, but often refers to a collection of different components or systems sometimes interchangeably. At its core, a database is an organised collection of data. This data is stored in different structures or in different formats, depending on the type of database. Relational databases, one of the most common types of database stored data in a tabular format.

The tables are made up of columns and rows, similar to how data is arranged in a spreadsheet. Each row in these tables is marked with a unique identifier known as a primary key. These keys are used to relate the data in rows, across different tables in the database and access information in different ways without having to alter the underlying tables. As well as the tabular structure of relational databases, several other popular database models exist. This includes dimensional databases are a specialised adaptation of the relational model built around a central fact table and used to support data warehouses. Object-oriented databases, borrow concepts from object oriented programming, representing data with objects rather than rows in a table.

NOSQL databases provide a variety of non-relational models that can store semi structured or unstructured data, including key value pairs. Surrounding databases, we have database management systems. Database management systems are a collection of programmes that enable you to create and maintain a database. Database management systems provide several key functions, including the ability to define a database, including specifying data types and constraints of the data to be stored. Construct the database, manipulate the database, including finding or updating data, Share the database to enable multiple users or programmes to access the database simultaneously. The database management system enables applications to interact with the database, processing queries or transactions. A query is a request for information.

And the transaction describes when data is written or read into the database. You’ll often find query is loosely used to describe any interaction with a database, including performing transactions, but it’s important to be able to distinguish between these at times. (gentle music)