To imagine a database management system (DBMS) will be much simpler with this metaphor: You are standing in the largest library on earth, trying to find a specific book. You are surrounded by countless books, but they are not ordered according to any apparent structure. How are you supposed to find the book you are looking for in this mass of books, aisles and shelves? How do you find it without going through each shelf and checking each book individually?
Most computers face a similar problem every day. This includes the transactions of your bank, the customer data in the company where you work or the location data of the warehouse from which your ordered package is shipped.
Enormous amounts of new data are produced everywhere and at all times. Without a well-defined organization system, this data resembles a useless pile of data. This is not only a waste of storage space, but also a potential to simplify business processes, to anticipate bottlenecks or to act in a more customer-centric way.
We therefore explain below how you can bring order into your data chaos with a database management system (DBMS) and save a lot of time as well as a lot of work.
What is a DBMS?
DBMS is the abbreviation for the bulky compound word database management system. But what is a database? What is a database system? And what does management have to do with it? Let’s start small.
Hardly any computer or web application works today without a database system. Technological megatrends such as artificial intelligence or the Internet of Things ensure that we are experiencing a veritable data deluge. By 2025, an estimated 175 zettabytes of data will be created worldwide.
For comparison: a 90-minute film requires about 500 megabytes of storage space. The amount of data in 2025 is equivalent to 350 trillion films – that’s a number with twelve zeros. Quite a lot of zeros, isn’t it? That’s exactly why data must be structured and put into a format that is readable for you. But how can data be stored in a structured way and made available to you as a user in the desired form? This is where DBMS come into play.
DBMS are part of a database system, which consists of two core components:
- a database
- a central administration interface, the DBMS
In the interaction of the two components, the database system enables you to store data in a structured way and to make it available in the desired form.
While the physical data is stored in the database, the DBMS controls access to the database. Generally speaking, the DBMS is software. It works as an interface between you as a user and the application, and takes over the task of organisation and structuring. A DBMS helps you to quickly and easily gain knowledge from the stored data.
To retrieve data from the database, there are special database languages. A well-known example is SQL (Structured Query Language). With the help of SQL, you can store, query and manage data records in the DBMS.
What are the components of a DBMS?
The DBMS enables you to access the database via an interface. However, you can only make database queries or use the data for other applications if you have the appropriate access rights. DMBS thus make an important contribution to security and data protection in your company.
In order to store data in a structured way and make it accessible, the systems consist of various components. The main components are
- the data definition language
- the data manipulation language
- the data dictionary
The data definition language (DDL) defines the actual structure of the database. You can create, change or delete individual objects such as references, relationships or user rights with the help of the definition language.
The data manipulation language (DML) is used to edit the actual data. In this way, you can delete, insert, change or read out data records.
The data dictionary has the task of providing all the information about the data stored in the database. This metadata, i.e. “data about data“, gives you information about the content of the various data in the data storage.
What DBMS models are there?
The way the DBMS structures and manages data depends on the database model. There are a variety of database models that are characterised by different properties.
The most common is the relational database model. Here you organise data in the form of tables. Each row forms a so-called entity, for example a film. Each entity has certain properties that you can read in the table columns. In our example, each film has a number of different attributes, such as title, genre or length. The advantage of relational databases is that a wide variety of relationships between data can be mapped and represented by values in table columns. It is important that you clearly distinguish the individual entities. To do this, you assign a so-called unique primary key to each row. In our example, this is a film ID that was generated automatically.
Figure 1: Data storage in the relational database model
The procedure is different with a hierarchical database model. Here, the data are related to each other in a kind of parent-child relationship. This model is represented by a hierarchical tree structure, which allows you quick read access. The top hierarchical level, the so-called root of the tree, represents the entire film collection in our example. In the individual leaves of the tree you will find the films and the attributes of the individual films.
Figure 2: Data storage in the hierarchical database model
Relational or hierarchical database models store structured data. But what happens when you want to manage unstructured data such as images or audio files? This data and information cannot be stored in the form of tables. So-called NoSQL databases were developed for this case. Here you organise the data in the form of key-value pairs.
What advantages do DBMS offer?
As the cornerstone of database systems, database management systems offer many advantages. Without the DBMS you would not be able to manage, control or monitor your database. In particular, it facilitates the management of large data sets. Through the structuring you can easily and quickly access stored data. Besides a high flexibility, the database management system also regulates the access of the users and can support you and your company in data protection.
Let’s go back to the example from the beginning: the confusing library. Wouldn’t it be helpful if the books were also organized according to a certain system? For example, we could assign a unique Book ID to the books and then sort them in ascending order on the shelves. Now, when you are looking for a certain book, you know exactly on which shelf and at which height you will find it.
As we all know, order is half the battle. Do you want to create more order in your database? Then we have the right resources for you. We are happy to help you and support your company to quickly and easily draw the right conclusions from the valuable company data. Let us advise you without obligation.
Sources
Wikipedia (2022): „Key Value Pairs“ [14.10.2022]
