The database management system (DBMS) is a software that is programmed to represent the features of its database model. The database model provides us the structure of how the data will be stored and managed. There are various database models each with its unique feature to store and manage the data in a database such as the hierarchical model, navigational model, object-oriented model, relational model, network model, etc.
The DBMS software is then added with an acronym to represent the particular database model such as The RDBMS represents the relational model, the OODBMS represents the object-oriented model, the ORDBMS represents the object-relational model, the DDBMS represents the distributed database model, CODASYL to represent the network model. Other extensions can indicate some other characteristics, such as DDBMS for a distributed database management system.
The DBMS is a general term to represent any database model but RDBMS is a term that specifically represents the relational database model.
Therefore when the DBMS software is particularly designed to represent the relational database model then it is termed as RDBMS.
DBMS + relational model = RDBMS
The RDBMS will be a DBMS, but every DBMS cannot be an RDBMS. The core difference Between DBMS and RDBMS is the relational model. The relational database model should adhere to rules that were made by the Father of Relational model and they are termed as Codd’s 12 rules.
The way we have discussed the difference between the DBMS and RDBMS is – As the DBMS is a system to control databases, therefore, we have discussed initially what is a database and what is the difference between database and DBMS. Then to understand how different database models lead to different DBMS systems we have discussed a brief history of improving database models that shaped the DBMS systems. Then to understand the RDBMS we need to understand its relational database model which we have covered. This will give you a crystal clear understanding of the difference between the database model and difference Between DBMS and RDBMS.
Now let’s discuss in detail what is the difference Between DBMS and RDBMS and how it gives rise to today’s technology.
Database and Database Management System
Before knowing about the RDBMS you must become familiar with DBMS which in turn leads you to the database. So, what is a database? Databases are organized collections of data that can be stored and accessed with the help of computer devices or electronically.
Sometimes the term DBMS is so loosely used with databases that the clear comparison is not visible. But the difference between the DBMS and the database is that the database is a collection of organized information but the DBMS is a software to manage one or many databases, it’s like the difference between water and glass, water has actual data but can be handled by the glass only.
In the physical form, the data can be the records of the student, the information about employees, etc. they are the raw data which form the data of the database and when we collect and organize this data it becomes our database, but the DBMS which can be a software or a technique helps users to define, create, maintain and control access to the database.
Also according to the model that the database follows to store the data, the DBMS acronym is extended to represent the model. The RDBMS represents the relational model, the OODBMS represents the object-oriented model, the ORDBMS represents the ORDBMS model, the DDBMS represents the distributed database model.
For a fun fact, the confusion of RDBMS and DBMS database models were used by the market to increase the sales. Codd, the father of the relational database model, had to fight campaigns to prevent the term ‘relational’ which was used by the database vendors who merely added the ‘relational’ term to their older database technology to increase the sales.
History of RDBMS acquiring earlier DBMS market
The database term became possible because of the growth and improvement in technology such as computer storage, computer memory, processors, computer networks, etc. which fueled the database and database management technology. The database term gained popularity when magnetic disks came into the market during the mid-1960s before this magnetic tape was used which stored the data in sequential form.
The database development can be divided into three development stages such as navigational to the relational era and then to the post-relational era.
The navigational era operated on magnetic disk technology and this method of storage involved the use of a pointer which guides the location of the next cell to place the data. In the navigational based system the storage occurred with the help of a linked list and the storage was done in a single length array and the destination of storage finding was the responsibility of the application programmer in the disk address. Before this, the data was stored sequentially one after another when magnetic tapes were in use. Also, the method used on the magnetic disk came to be known as the hierarchical model (Starting point of database models), this model has a connection between stored data as a tree structure – parent node branching to many child nodes.
In this era, the software that was made to manage the database model such as hierarchical, CODASYL, network model were the DATABASE MANAGEMENT SOFTWARE (DBMS) and not the RDBMS which will operate on relational databases.
The navigational era ended when in 1970 Edgar F. Codd proposed the relational model for the databases which marked the beginning of the relational era. In this database model, this model used a ledger style table and the applications were made to search with the help of content rather than pointers. The storage of data in this model involved the use of relations(table) which consists of record(rows) and attribute(column). This model has many benefits such as it can support transaction and concurrency, role-based authorization, relational calculus performed on data, introduction to keys, Enforcing constraints so data should abide by some rules and this relational model introduced many features that put down the previous database model. Only by mid-1980, computer hardware became powerful enough to support this relational model and then MySQL and Oracle dominated the industry of data processing which could support the relational model.
In this era, the software and applications that were made to manage the relational model of the database were called the RELATIONAL DATABASE MANAGEMENT SOFTWARE (RDBMS).
Post Relational Era
Along with the relational era, technology advancement took place rapidly the internet became popular and the data was flowing in more formats than we had ever imagined. Along with the structured data, the unstructured data also became popular. The unstructured data could not be stored in the table format such as audio, images, thousand lines of text, etc. and hence the post-relational era started involving technology such as NoSQL and NewSQL.
Relational Database Management System (RDBMS)
Edgar F. Codd [Father of Relational database Model]
Edgar F. Codd worked at IBM in California. He was in charge of development mainly related to the hard disk. Edgar was upset by the navigational model of the CODASYL, the earlier DBMS system. He said the navigational model lacked the “search” facility. The navigational method used a linked list and used a reference to the next address to add the new data with the help of a pointer, also there was a primary key that showed a relationship with records.
After that Codd wrote a series of paper introducing the idea about how the data can be stored in form of “tables” and how tables can store the data in rows ( tuples ) and column ( attribute ) and the relationship or cross-reference between more tables can be done with the help of primary key rather than address that was used in the linked list.
The relationship between tables can be performed with the help of a set of operations that is based on a mathematical model of Relational Calculus, and that’s from where the relational DBMS derived it’s Relational (R). Edgar was more interested in the development of mathematical models which can easily define and update the database with the help of clean mathematical definitions, which was the heart and soul of the relational calculus.
Features that only RDBMS offered
Some of the main features that define the relational database model and thus the relational database management system are:
1. The data is represented in tabular form and also in a collection of tables. Each Table has a set of rows and columns which contain the data.
2. The RDBMS also provides a relational operator and these relational operators can perform mathematical operations as in set theory. These relational operators can be performed on one or more tables at the same time treating the tables as the set collection and the records in the set as the elements of the set.
3. The navigational model used the linked list method, and to store the new data the pointer has to point into some disk address which was empty to store the new data. But in relational database models, to store more data the concept of the key can be used.
4. The concept of the key was brought to major use in RDBMS. Rows in one table can be linked to the rows in another table with the help of a column as a unique key, this column will represent the link between the tables and this column can be known as the primary key of the tables, which can uniquely identify the rows.
5. The Relational database management system can support the transaction-based system. For a full-fledged transaction system, the DBMS should follow the ACID (Atomicity, Concurrency, Isolation, Durability) properties, and the RDBMS system has protocols to fulfill all the ACID properties for the transaction.
6. The normalization features of the relational database management system help the data in the database to remain consistent and remove any form of redundancy that exists in the database. The normalization is done step by step – 1 NF, 2 NF, 3 NF, BCNF. When the database is passed through these stages many records are removed and a more consistent database is formed.
DBMS Vs RDBMS Ending Note:
I have put my complete effort to bring to you the difference between the DBMS and the RDBMS, if you want more detailed information then I will suggest you go through this Wikipedia article which will give you the complete history and features of each model and help you understand how each database model shaped the Database Systems.