Databases and DBMS

Before we start learning SQL, let's get acquainted with the basic concepts of databases. This will help us understand the scope of SQL and the environment it operates in.

A database is a set of data stored in a structured way

In fact, this is just a repository of some information, nothing more. Databases themselves would be of no interest if there were no database management systems.

A database management system is a set of software tools that provides access to data, allows it to be created, modified and deleted, ensures data security, and so on.

In simpler terms, a DBMS is a system that lets you create databases and manipulate the information in them.

The simplest scheme for working with a database:

Database operation scheme

DBMS rating

At the moment, the rating of database management systems based on db-engines is as follows:

Oracle - relational DBMS
MySQL - relational DBMS
Microsoft SQL Server - relational DBMS
PostgreSQL - relational DBMS
MongoDB - document-oriented databases
Redis - key-value databases
Snowflake - cloud relational DBMS
Elasticsearch - search engine
IBM Db2 - relational DBMS
SQLite - relational DBMS

It can be noted that 7 of the 10 most popular DBMS are relational. You made the right choice to study them 😉.

Let's check how we learned the topic, choose the correct statement: