 I am Assistant Professor from Department of Electronics from Walter Engineering College, Singapore. So today we are going to have an session on Introduction to DBMS. At the end of this session student will be able to define the term data database DBMS database system, differentiate between the database approach and traditional system and enlist and describe different types of database and users. So we are going to start with introduction to DBMS. So firstly we need to know what is data. So data is nothing but facts and statistics that can be recorded for reference or analysis. For example, text, numbers, videos, speech, audio, video, etc. Let's take an example of Ola and Uber, they don't have their own caps. They are having the data of the caps and they provide it to the customers. Even if you take the example of online shopping, when you open the social media websites like Facebook or Instagram, Twitter, what they do, they flash you the products you have searched. Why this is so? Because they have recorded your search engines. So this is the data which is nothing but the facts and statistics that has been recorded. What is information? Information can be processed data or the meaningful data. Like for example, YouTube, when you open the YouTube, you have millions of videos. But what is information? You open the search tab and you search for the videos which is required by you. That is for example, if you search the video for introduction to DBMS, that is the information for you. Next is what is database? Database is a collection of related data that represents the real world or the mini world. Database is logically coherent collection of data with some inherent meaning. A random data cannot be correctly referred as database. Database is built and populated with data for specific purposes. In other words, you can say database to be accurate and reliable at all times. It should be reflection of mini world or the real world. If you go with the examples, it will be clear for you. Here the recorded data of that person with the name, telephone number and addresses is the database for you. And if you go for the faculty database, university or the college is having database for the faculties. They record all the information of the faculties and even if the faculty gets resigned or even if he gets married or if he has his dependence, all the data is recorded in the faculty database. So we can say database is nothing but it is a reflection of the real world. So whatever is happening in the real world, it should get updated into the database. What is database management system? Database management system is nothing but database plus management system. A database management system which is DBMS is a collection of interrelated data and a set of programs to access that data. A primary goal of DBMS is to provide a way to store and retrieve the database information that is both convenient and efficient. DBMS is a computerized system that enables the user to create and maintain the database. So why we are going to use the database management system? You are familiar with the client server architecture. The figure in the right side shows you the client server architecture. In the between, you have the server and you have the clients all over the server. So you are the users with the laptop or computer mobile phones. They are nothing but the clients and the server is nothing but where the data is been stored. If you take the example of the IRCT website, so if you want to search for a particular train and if you consider like 25 GB of data is present in the IRCTC website and you want to search only 1 KB of data of that particular train and if you are going for the file processing system, then what you have to do? You have to download all the 25 GB of data onto your computer or laptop or you can say the local drive and then you have to go for searching of 1 KB of data from that 25 GB of data. This is so much of complicated, so much of time consuming also that you have to download all the 25 GB and then search the 1 KB of data. But if you go for the database management system, you have not to download all the 25 GB of data. You have to log into the server and just search for that 1 KB of data. That is so easy. This is the beauty of DBMS. We'll see the features of the database management system comparing it with the file processing system. First feature is the location. When you go for the file processing system and you want to access one file in the file processing, you have to know the location of that file. Like if you are searching for file in your PC or the laptop, you know the location of their local drive, then folders, then subfolders and everything. But in your database management system that is DBMS, you need not to know the location of your file. The beautiful example for this location feature is when you open a YouTube and you go for searching of any video, you need not to know the location of that particular video. You can simply search for that particular video and you can access it. But if you go for the file processing, you need to know the location of the file. Then only you can access it. Next is the concurrency control. What is concurrency? Concurrency is nothing but a multi-user feature. So if you are using the file processing system and if you want to share file with your friend or someone, what you need to do? You need to share the file or you need to give your laptop or PC to some other so that you can access it. But in the database management system, whatever database is there or whatever the data is there, it is stored in the server. You just need to login into it and access it. So you can have multiple users sitting at your home. No need to give the access to your devices. So whatever data is there, it is in the server and you have to access it using the clients. So this is a feature for the concurrency which will provide you the feature of multiple user at a time. So this is not possible in the file processing. Next is the security, which is role-based system. Example of university if you take student, faculty and the HOD. So these are the three role plays we are going to see. So when you go for the student, student is able to see only the name, address, phone number and the subjects of that particular student. So he is not able to or he is not allowed to view the data of the faculty. What are the faculty database and all. But when you go for the faculty, faculty is able to view the data of that particular student of his subject not allowed to view the information of other faculties in that department. Only his data and his student's data he can view. And the other role is HOD. So HOD can view the information of the faculty student as well. But he cannot view the information of other department HODs. So database management system provides a security which is called as role-based security. So you can provide the restrictions that student cannot view the faculty information, faculty cannot view the other faculty information and HODs cannot view the other HODs information. Such type of role-based or security is provided in the database management system. But this security is not provided in the file processing system. Next is the data redundancy. So data redundancy is nothing but data duplication. If you take the example of lab assistant of one particular department and the office administrator. So these two persons are going to have the data of one particular XY student. Data redundancy is nothing but data duplication. The same information is recorded by the two different users. If you go through the diagram over here, the left side which is the file-based approach. So the same data you can see the set, this is intersection set and same data is being stored by the two different users using two different applications. And the right side what you are having is the database approach. You are having one single database which is common for both the users. And the both the users are going to access this database using one single DBMS software. Which is in your case you can see data is wisely stored you can see. So same data is stored by two different users. So this is nothing but example of data redundancy you can see. Next go for the file processing system and the database management system differentiate. So first is file system is general easy to use system to store general files which require less security and constraints. So whenever there is a less security you can go for file processing system, when there is more security you can go for the database management system. Data redundancy is more in the file processing system. Because when you go for file processing system, duplicacy of data is happening in the file because both the users are going to save the same data of that particular user. Next is the data redundancy. Data redundancy is less in the database management system. As seen in the previous slide only one single database is going to access by the two different users. Centralization is hard when it comes to the file processing system. And centralization is very easy and it is achieved using the database management system. Next is user locates the physical access of the files to access the data in the file processing system. But in database it is user is not aware about the physical location of the data where it is stored. Next is security is very low in file management system and security is very high in the database management system. So you can say with the help of role based model we have seen the difference of the how the security is very low in the file system and how security is high in the database management system. So these are the references of the database systems by Ramesh and the Shamkand B Naute. Thank you.