Computer databases are used in a large number of businesses to store, organize and analyze data. Find out everything you need to know about it: what is a database, what is it for, how does it work, what are the different categories, and which are the best.
A database (which we will call BDD for convenience) is a collection of information organized to be easily consultable, manageable and updated. Within a database, data is organized into rows, columns and tables. They are indexed so that you can easily find the information you are looking for using computer software. Each time new information is added, the data is updated, and possibly deleted.
What is a database? Definition
They are responsible for creating, updating or deleting data themselves. They also perform searches among the data they contain at the user’s request, and launch applications from the data.
Databases are used by many businesses across all industries. They are used in particular by airlines to manage reservations. They are used for production management. For medical recordings in hospitals, or for legal recordings in insurance companies. The largest databases are typically used by government agencies, large businesses, or universities.
How do databases work?
Databases are stored as files or a set of files on a magnetic disk, cassette, optical disk, or other type of storage device. Traditional (hierarchical) databases are organized by fields, records and files. A field is a single piece of information. A record is a collection of fields. A file is a collection of records.
For example, a phone book is the equivalent of a file. It contains a set of records, and each record has three fields: name, address, and phone number. As an example, we can also cite product catalogs or inventories.
The ability to consult or modify a database (read or write) is conferred on various users by a database manager. Databases are mainly present within the largest mainframe systems, but they are also found within smaller distributed workstations and other midrange systems such as IBM AS/400s or even personal computers.
The history of databases
The history of databases dates back to the 1960s, with the emergence of network databases and hierarchical databases. In the 1980s, object-oriented databases appeared. Today, the predominant databases are SQL, NoSQL and cloud databases.
It is also possible to classify databases according to their content: bibliographic, texts, numbers or images. However, in computer science, databases are generally classified according to their organizational approach. There are many different types of databases: relational, distributed, cloud, NoSQL… Here are the different types of databases.
What are the different types of databases
In the case of a large database, multiple users must be able to manipulate the information it contains quickly and at any time. Additionally, large companies tend to have many independent files that include linked files or even overlapping data. As part of data analysis, it is necessary that data from several files can be linked. This is why different types of databases have been developed to meet these requirements: text-oriented, hierarchical, network, relational, object-oriented, etc.
Hierarchical databases are among the oldest databases. Within this category, records are organized in a tree structure. Each level of records flows onto a set of smaller categories.
Network databases are also among the oldest. Rather than providing single links between different sets of data at various levels, network databases create multiple links between sets by placing links, or pointers, to one set of records or another. The speed and versatility of network databases have led to massive adoption of this type of database within businesses or in the field of e-commerce.
A text-oriented database, or flat file database, is in the form of a file (a table) in .txt or .ini format. A flat file is a text file, or a file combining text with a binary file. Typically, in these databases, each row has only one record. Most PC databases are text-oriented databases.
SQL database (relational)
Relational databases were invented in 1970 by E.F. Codd of IBM. These are tabular documents in which data is defined so that it is accessible and can be reorganized in different ways.
Relational databases are made up of a set of tables. Within these tables, the data is classified by category. Each table has at least one column corresponding to a category. Each column has a certain amount of data corresponding to that category.
The standard API for relational databases is Structured Query Language (SQL). Relational databases are easily extensible, and new data categories can be added after the original database is created without needing to modify any existing applications.
A distributed database is a database of which portions are stored in several physical locations. Processing is distributed or replicated between different points on a network.
Distributed databases can be homogeneous or heterogeneous. In the case of a homogeneous distributed database system, all physical locations operate on the same hardware and run the same operating system and the same database applications. On the contrary, in the case of a heterogeneous distributed database, the hardware, operating systems and database applications may vary between different physical locations.
In this context, it is optimized or directly created for virtualized environments. This can be a private cloud, a public cloud or a hybrid cloud.
Cloud databases offer several advantages such as the ability to pay for storage capacity and bandwidth based on usage. Furthermore, it is possible to change the scale on request. These databases also offer higher availability.
NoSQL databases are useful for large distributed data sets. Indeed, relational databases are not designed for Big Data, and datasets that are too large can cause performance problems.
If a business needs to analyze large amounts of unstructured data, or data stored across multiple virtual cloud servers, the NoSQL database is ideal. With the rise of Big Data, NoSQL databases are increasingly used.