Everything you wanted to know about databases: types, features and examples

The volume of information is steadily growing and requires organization. Every developer inevitably comes to the need to create a database. Whether it is a website, an application or a corporate project – with the growth of users, you cannot do without a correctly selected database. What types of databases there are, we will tell you in this article.

What is a database?

A database is a set of information that is structured in some way. The logic of data distribution in a database depends on its type and the project objectives.

The most common databases today are seen in the form of tables. They are indeed visually similar to the spreadsheets we make in Excel, but they have fundamental differences:

• Regular spreadsheets are usually single-user, and if several users have access to them, then control and capabilities are limited. In databases, this problem does not exist: users can make changes simultaneously, independently of each other and without restrictions.
• The amount of information stored in a spreadsheet may be sufficient only for a short time, if we are talking about projects. Databases, on the other hand, provide for working with larger volumes of data and greater opportunities for making changes.

DBMS ( Database Manager System) are used to manage databases . DBMS, as software, allows:

• create, edit and manage databases;
• work with the database simultaneously for several users;
• simplify work with databases, including reporting, backup, basic database operations, etc.

Initially, this language was the basis for working with databases, allowing you to create tables in the database, add, change and delete records in tables, perform data selection, etc. Over time, SQL became more complex and began to offer database users more spam number data opportunities. A complete guide to SQL can be found here , and a style guide here .

At some point, DBMS owners began using SQL dialects that differed from the original standard. Today, responsibility for compliance with the working with databases in loginom standards lies solely with the creators of the various DBMS.

Since the SQL language is used in relational DBMSs (we will talk about them below), in the second half of the 2000s, noSQL followers began to ar numbers appear. They abandoned the relational model, which is why today there are graph, document and other types of DBMSs.

What are databases for?

The creation and development of databases is primarily due to the need to collect, store and process a large amount of data. In this case, the information must be structured, since it will be regularly used and changed.

Conventional methods of storing data do not allow managing them in multi-user mode without restrictions. Databases solve this problem by providing the ability for several users to add and change data at once. Information security of databases involves protection from unauthorized access, destruction of information, as well as software and hardware errors.

Types of databases

Even today, you can find the use of the simplest types of databases. For example, in text form (in txt, csv, etc. formats).

Network databases can now have more complex relationships, but there are still limitations.

More complex and common data models include relational, non-relational and combined.

Relational databases ( SQL databases )

The relational data model is one of the most common. A relational DB is a set of tables that are linked together. The rows of a table contain data about one object (for example, a client, a website user, a product), and the columns describe the characteristics of these objects (for example, the client’s email address, a product code).

A feature of relational databases is the formation of clear relationships: foreign keys (links to other tables), which are responsible for the relationships between tables of the entire DB.

For example, when adding a new product record to the table, we can immediately link it to a specific product category (food, household appliances, etc.) We can also add and change categories. In this case, the new product and a specific category will have their own identifiers (for example, a specific id_item number and id_category).

DBMSs offer users a convenient graphical interface, making working with the DB much easier, but knowledge of basic SQL queries is necessary.

However, the structured approach of relational databases has its drawback. Often we encounter data that is difficult to structure and enter into a table.

Non-relational databases ( noSQL databases

Key-value databases are the simplest type of non-relational databases. They consist of a key and a data object. At the same time, it is possible to store different types of data under one key, search and “delivery” of data is quite fast due to address storage.

The disadvantages of such databases are the long search not by “key”, but by “value”, as well as the impossibility of quick analytics and statistics collection.

Graph databases resemble network databases, but with stronger connections, which makes them convenient, for example, for social networks.

Combined databases

The NewSQL approach emerged in the early 2010s with the aim of combining the advantages of relational and NoSQL databases. Despite high resource requirements and the need for technical knowledge, such databases provide high scalability and performance.

Ac

• Multi-model

ArangoDB, OrientDB

The advantage of multi-model DBs is undoubtedly the ability to use different models of data representation. In this case, users have the ability to manage information located in different databases with different approaches.

This way, you can scale, use different types of data and integrate them into the structure without breaking its integrity.

Cloud DB

I would like to highlight cloud databases separately, which operate using cloud technologies. Users install software on the cloud infrastructure to deploy the database. There are no restrictions on SQL or NoSQL types of databases.

A cloud database has a higher level of flexibility, and the cost of using cloud capacity depends only on the resources spent. Some providers use automation tools, which reduces the risk of human errors (autonomous databases).

How to choose a database: database rating

The described types of databases provide a wide choice for any business, site, project or application. What to rely on when choosing a database:

• the task of your project (website data management, application, analytics, etc.)
• in what format to store information
• how to structure and access information

If you want to make a choice based on popularity among other users, on DB-Engines you will find a rating of various DBMS. For example, as of February 2023, the TOP-5 included: Oracle, MySQL, Microsoft SQL Server, PostgreSQL and MongoDB.

In times of increased importance of large volumes of information, databases are a necessity. Different approaches to data models give commercial and non-commercial organizations a choice of DBMS.