Database Management System, often called DBMS, is the combination of computer programs in a software package primarily designed for the creation, maintenance, and use of databases by following proper security standards. DBMS acts as an intermediate between the database and the end-user or third-party software. With DBMS, users can create, access, or manipulate data in the database.
In this article, we explain some of the major characteristics of DBMS found these days. However, they are not limited to these characteristics discussed in this article. Depending on the architecture and future upgrades, there may be many more characteristics of a database management system.
What are the characteristics of DBMS?
Before DBMS, files were stored using the traditional file system. DBMS was a completely new concept at that time. However, DBMS has gone through many updates and additions to overcome all the problems or shortcomings of the traditional file system. Modern DBMS are comparatively very advanced than file-based systems. Key features of modern DBMS typically include a real-world entity, low redundancy, concurrent access, data consistency, security & integrity, support for SQL, ACID properties, and transaction support.
Following are the common characteristics of DBMS (Database Management System):
DBMS Characteristics List [Show/ Hide] • Real-World Entity • Relational Databases • Self-Describing Nature • Supports Multiple Data Types • Data Schema • Multiple Views • Structured Query Language • Insulation of Data and Application • ACID Properties • Multiuser and Concurrent Access • Object-Oriented Programming • Transactional Processing • Data Mining • Distributed Database Systems • Less Redundancy and Consistency • Data Persistency • Data Security and Integrity • Backup and Recovery • Cost • Users
Real-World Entity
Database management systems are realistic these days and take advantage of real-world entities when designing the architecture. They are specifically designed for the needs of any business or organization, allowing them to efficiently manage and maintain large amounts of data. Modern DBMS also makes of use behavior and attributes.
For example, an organization database might use employees as entities and their age or IDs as attributes.
Relational Databases
With relational databases, data is organized or stored in a structured format within tables formed by rows and columns. Due to this, it becomes easier to locate or access particular values in the database.
The word relational here denotes that the values stored in each table are related to each other. Similarly, tables can also be linked to each other to form relationships. The relational structure simplifies the concept of data saving and makes it possible to run queries on multiple tables of the database simultaneously.
Self-Describing Nature
Before DBMS, the traditional file system was the only option for storing data. However, it lacked a self-describing nature. In DBMS, the data is stored along with the metadata. Since metadata is maintained automatically in the DBMS, the DBMS reflects a self-describing nature. Metadata refers to a piece of additional information about the actual data, such as file name, format, file creation date, last modification date, etc.
Supports Multiple Data Types
The database management system these days are capable of storing any kind of data. It is not just limited to any specific file types. It can hold any typical data we come around in the modern world. For example, binary, numeric, string, dates, etc.
Data Schema
In a DBMS, data is stored within tables that are structured before the data is written. This structure of the table is commonly known as a schema in DBMS. It contains information about various attributes related to the data. For example, tables, fields, packages, views, relationships, primary key, foreign key, etc.
The data is not physically stored in the schema; instead, it is simply the logical representation of the database that is used to demonstrate how the data is stored logically within the database. Since data is stored physically in files in an unstructured form, it needs to be structured or organized in order to be used or searched. This is where the schema is used.
Multiple Views
Modern DBMS provides multiple views of the database, allowing users to view the desired database in a number of ways based on department, category, or any other attribute. It is entirely based on how the view access of the database has been specified.
For example, an organization database may have a different view when accessed by HR, and a different view when accessed by an employee. The database remains the same but different users may have a different view of the information, which strengthens the security of the database information.
Structured Query Language
Structured Query Language, abbreviated as SQL, is the query language that helps users create queries to access or modify data in database management systems. They are called structured because they use predefined structures to form relationships between entities. These queries use specific commands, written in English, with keywords that instruct the database on which actions are to be performed. This is not possible with file-based systems.
Insulation of Data and Application
The database system (or application or program) and the data stored in the database are completely different from each other. The database is called the active entity in DBMS, while the data is called the passive entity through which the database itself operates. In particular, both are independent.
Due to the independent approach, DBMS has an advantage over the traditional file-based system. Unlike a traditional file-based system, the structure of the data files is not defined or stored in the application in DBMS. Instead, it is defined in the system catalog, making it easy for users to make changes. This means that changes made to the data or any internal improvement in data efficiency will not affect the application program.
But, with the traditional file-based system, users have to replace the entire application program that uses the associated data files. In this way, DBMS provides better insulation of data and application.
ACID Properties
The database management system supports the concept of ACID (Atomicity, Consistency, Isolation, and Durability) properties. These properties ensure that the primary purpose of any DBMS system is not lost while performing specific tasks like inserting, deleting, modifying data in the database. ACID properties also help in maintaining a healthy state of the database in the multi-transactional environment or sudden failures.
Multiuser and Concurrent Access
DBMS provides a multi-user environment, allowing multiple users to work with data in parallel or concurrently. This is one of the primary advantages of DBMS. Due to concurrent access, multiple users access the database at the same time and perform specific operations without any problems. For example, a railway reservation system is used by several people at a time and people book tickets simultaneously until the seats are completely filled or blocked.
Object-Oriented Programming
Object-Oriented Programming, commonly referred to as OOP, is a special technique used in DBMS to design programs. Objects hold properties as well as methods. While properties denote variables or constants that carry values, methods represent processes that act on related properties.
Unlike other programming approaches, OOP enables the programmer to create reusable components by encapsulating their functionality within classes. Classes incorporate a specific set of code and other data elements. Instead of writing the same code multiple times, programmers prefer to use classes.
Transactional Processing
DBMS supports transactional processing that helps the users to maintain the stability of the database. In DBMS, transactions represent the set of operations performed to bring the database from one stable state to another or a new stable state. These transactions are atomic, which means they will either be complete or remain incomplete.
With transactional processing, the DBMS ensures to roll back the transaction if there is an error or failure while it is running. This keeps the system stable, keeping the entire system running continuously while multiple users are accessing it simultaneously.
Data Mining
Data mining, also known as Knowledge Discovery in Database (KDD), refers to the process of extracting essential information from large databases (or big databases). The process generally helps in identifying trends and patterns among different data sets from the database in a DBMS, improving decision making.
Various data mining algorithms are used in DBMS. Some such algorithms are classification, association rules, regression analysis, decision trees, neural networks, genetic algorithms, etc.
Distributed Database Systems
A DBMS supports distributed database systems, which means that it stores data across multiple computers connected to a network. Due to the distributed database concept, it is easy to scale or include additional servers without the need to set up an entire environment from scratch. In a DBMS, a distributed database typically includes the following parts: Client Applications, Server Applications, and Shared Storage.
Client applications help to access shared storage with multiple protocols such as TCP (Transmission Control Protocol) and IP (Internet Protocol). Server applications help in delivering essential services to the clients. Shared storage helps to allocate the desired storage space to hold all the data. At the same time, each node in the cluster holds or stores the metadata of the other nodes.
Less Redundancy and Consistency
Data redundancy refers to the problem of having the same data unnecessarily in more than one place in the database. With DBMS, redundancy is reduced or nearly eliminated compared to traditional file systems. DBMS follows the concept of normalization which splits a relation when there is redundancy.
DBMS maintains consistency of data, which means that the data remains correct at all times for all users. Changes based on data modification or manipulation are reflected in the database without any problems, keeping the relationships in the database consistent.
Data Persistency
With DBMS, data is persistent which means that the data is kept and maintained in the database by the DBMS until it is explicitly deleted or removed by the user. In case of uncertainty like system failure, there is the least to zero chance of data loss. The life span of the stored data is entirely decided by the authorized user. If the system fails in the middle of a transaction, the entire process or even system is rolled back, keeping the data safe to the maximum extent possible.
Data Security and Integrity
DBMS provides the highest security to the stored data as it provides different levels of security features. This allows primary users or administrators to enforce the necessary constraints to access the data. Because of this, users will only be able to access the data by a specific security PIN or password.
Furthermore, since the DBMS renders multiple views, different users can only access the data individually allowed to them. For example, a person in the sales department cannot see information related to purchases and vice versa.
Apart from data security, DBMS also maintains data integrity. This means that it ensures the quality and reliability of the data in the database. It prohibits all unauthorized access. Since the data is not stored on a disk with the DBMS, it is almost impossible for fraudsters to break the security and access the data.
Backup and Recovery
Backup and recovery are two effective features in a DBMS that help the users to avoid any damage to the stored data. With a DBMS, users can back up the data stored at certain points and restore the backup to get the data back in case of uncertainty.
Modern DBMS also takes care of the backup and restore of the system automatically. The data is backed up automatically as per the schedule and is automatically rolled back when a failure occurs, keeping the system stable.
Cost
The cost required to set up a DBMS is a notable characteristic as it can be quite high compared to other data storage software or technologies. The cost of a DBMS can create confusion about whether to choose it or not. However, if an organization is looking to store a large amount of data for a long period of time, a DBMS can be the best option and its maintenance cost will be comparatively less over time.
Users
Users are important elements or components in DBMS as there are different users to perform specific tasks. Some users may be involved in creating or designing DBMS, some may be involved in backing up data, some may be involved in setting up access permissions, some may be end-users, etc. Typically, database administrators (DBA), designers, and end-users play a key role in a DBMS environment.
Summary
This article discusses about 20 characteristics of a database management system. Modern DBMS has many features or characteristics and DBMS vendors are always working towards adding more and more to compete with each other. Some of the popular examples of database management systems are MySQL Database, MS-Access, Oracle Database, Microsoft SQL Server, etc.
What others reading:
• Disadvantages of DBMS • Components of DBMS • Difference Between DBMS and RDBMS• Difference Between Data and Information