In today’s professional world, mastering databases is essential to optimize the management and exploitation of information. This guide presents everything you need to know to get started in the field of databases. You will discover the main concepts and terminologies, as well as the criteria for choosing a database management system.
Fundamental concepts and terminologies
To get started with databases, it’s important to understand the fundamental concepts and terminology. This section will introduce you to the key things to remember.
The relational model
The relational model is a data model based on set theory. It allows data to be represented and manipulated in the form of tables composed of rows (records) and columns (attributes). The relational model is used by the majority of current database management systems.
Entities and Relationships
In the context of databases, an entity is a real or abstract object that can be uniquely identified and has attributes. Relationships describe the links between entities. For example, an “Employee” entity can be linked to a “Company” entity by a “Works for” relationship.
CRUD operations
CRUD (Create, Read, Update, Delete) operations are the four basic operations for manipulating data in a database. These operations allow you to insert, read, modify, and delete data.
The SQL language
SQL (Structured Query Language) is a standardized query language for communicating with relational databases. It allows CRUD operations to be performed, as well as complex queries to extract data based on specific criteria.
Database Types and DBMSs
There are different types of databases and database management systems (DBMS). This section introduces you to the main types of databases and the most popular DBMSs.
Relational databases
Relational databases are based on the relational model. They are ideal for managing structured and normalized data. The most popular relational DBMSs include MySQL, PostgreSQL, Microsoft SQL Server, and Oracle Database.
NoSQL databases
NoSQL (Not only SQL) databases are alternatives to relational databases for managing unstructured or semi-structured data. They include several types of databases, such as document-oriented databases (MongoDB, CouchDB), column-oriented databases (Cassandra, HBase), graph-oriented databases (Neo4j, ArangoDB), and key-value-oriented databases (Redis, Riak).
NewSQL Databases
NewSQL databases are a new generation of relational databases that seek to combine the benefits of relational and NoSQL databases. They offer high availability, high scalability, and better performance for online transactions. Examples of NewSQL databases include CockroachDB, VoltDB, and MemSQL.
Criteria for choosing a DBMS
Choosing a DBMS depends on several criteria. This section presents the key elements to consider when selecting the right DBMS.
Data needs
Assessing data needs is essential to choosing the right DBMS. Questions to ask include: How much data will be managed? Is the data structured, unstructured, or semi-structured? What are the performance, availability, and security constraints?
In-house skills
In-house expertise is an important criterion for choosing a DBMS. It is best to choose a DBMS that the team is already familiar with, or that has a large community and resources to facilitate learning.
Cost and license
Costs and licenses are also a consideration. These include the cost of acquiring, installing, and maintaining the DBMS, as well as the costs associated with licensing its use. It is important to consider open-source solutions such as PostgreSQL or MySQL, which are often free and offer excellent performance.
Conclusion: Getting started with databases
Getting started with databases requires understanding fundamental concepts and terminology, understanding the different types of databases and DBMSs, and choosing the right DBMS based on data needs, internal skills, and cost. By following these tips, you’ll be able to get started and optimize information management and exploitation in your organization.
