Databases Introduction


The topic of databases in the IT world is a big topic. If you’re are a programmer, you can’t get away from knowing at least something about databases. For example, at this website, we are using WordPress. The interface you are looking at is what your browser (or mobile device’s browser) is rendering on the screen, but behind that is a mySQL database that WordPress is using to grab the text you are reading, among other things. It is important to in your mind separate the concepts of presentation (formatting and layouts) and the underlying data.

Wikipedia says this about Databases: “A database is an organized collection of data. It is the collection of schemas, tables, queries, reports, views, and other objects. The data are typically organized to model aspects of reality in a way that supports processes requiring information, such as modelling the availability of rooms in hotels in a way that supports finding a hotel with vacancies.”

Wikipedia says this about Data: “Data (treated as singular, plural, or as a mass noun) is any sequence of one or more symbols given meaning by specific act(s) of interpretation. Data (or datum – a single unit of data) is not information. Data requires interpretation to become information. To translate data to information, there must be several known factors considered. The factors involved are determined by the creator of the data and the desired information. The term metadata is used to reference the data about the data.”

Wikipedia says: “A computer program is a set of data that consists of a series of coded software instructions to control the operation of a computer or other machine.”

Wikipedia says: “A database management system (DBMS) is a computer software application that interacts with the user, other applications, and the database itself to capture and analyze data. A general-purpose DBMS is designed to allow the definition, creation, querying, update, and administration of databases. Well-known DBMSs include MySQL, PostgreSQL, MongoDB, MariaDB, Microsoft SQL Server, Oracle, Sybase, SAP HANA, and IBM DB2.”

Wikipedia says: “Database management systems are often classified according to the database model that they support; the most popular database systems since the 1980s have all supported the relational model as represented by the SQL language. Sometimes a DBMS is loosely referred to as a ‘database’.”

Types of Databases

There is an article over at IBM called A Brief Overview of the Database Landscape.