How is data stored in a database

Data storage / data management

What kind of data storage does the software support?
Structured data storage

For the selection of a suitable data backup concept as well as for the administration and infrastructure required later, it is necessary to know the data storage method required for the software used. In the following, models and terms for data management are explained. This essentially involves databases and file systems, which are the basic components of efficient data management.

Advantages of a database system

There are clear advantages for a database system compared to a simple file system:

  • It offers a common, often central, basis for all applications
  • The redundancy becomes controllable because the data is only kept in one place
  • Inconsistencies are avoided
  • The query language generally allows relatively simple application programming
  • The widely used query language lowers costs for administration, data maintenance and data analysis)

Structured data storage

Databases store data in a structured form. The structure makes it possible to find and edit data. With their structured structure, databases are used for data management, data storage, data evaluation and targeted processing of data. In this sense, data is all information that is to be saved and later reused in various contexts. These can be date and time values, texts, addresses, numbers, but also pictures. The data should be able to be evaluated and processed later.

Data only becomes meaningful when they are related to each other. A street name with house number only becomes an address if it includes a name (addressee) and a place. A database provides structures with which data can be related to one another. It does not create the relationships itself - only the person who creates or manages the database can do that. However, the structure makes it possible to find, evaluate and process the data again.

Tables

A well-tried structure for relating data to one another is using tables. Lists in simple or tabular form are among the oldest written records of people. Data that belong together are listed in columns and rows. The so-called relational databases also work with tables. The rows contain data that belong together and are divided into categories by the columns.

Relational databases advantages and features

  • the data is stored in tables
  • all fields of a column / table are always the same width and contain only one data type
  • the number of columns is not limited in theory
  • the structure of the database can be changed without having to change software applications
  • Parts of tables can be combined
  • Any number of different views are possible
  • Creation of different, logical structures as so-called virtual tables for analytical views

The relational database model has proven to be unsuitable for some "non-standard" applications. Object-oriented databases are used here. Such applications include:

  • computer-aided engineering systems (CAD and CAES systems)
  • computer aided software development
  • Multimedia and hypermedia applications

Relational database

In a relational database, for example, data records from two tables can be linked with one another using a key. One speaks of a primary key and a foreign key.1

Object database

“An object database or object-oriented database is a database that is based on the object database model. In contrast to the relational database, data is managed here as objects in the sense of object orientation. The associated database management system is referred to as the object-oriented database management system. The object database and the object database management system together form the object database system. "2

Key-value databases3

"In principle, key-value stores are even simpler: A certain key refers to a value which, in its simplest form, can be an arbitrary string."4