Lec-3: File System vs DBMS | Disadvantages of File System | DBMS Advantages

File System vs DBMS: Understanding the Transition

Introduction to File Systems and DBMS

• The discussion begins with an overview of the transition from traditional file systems to Database Management Systems (DBMS), highlighting the need for a more efficient data management solution.

• A real-life example from the 1970s illustrates how users accessed data through file systems, managing their data in files and folders on personal drives.

Limitations of File Systems

• The speaker questions why DBMS is necessary if file systems are functioning adequately, setting up a comparison between both systems.

• Emphasis is placed on client-server architecture, where data is centralized and accessible by multiple users globally, contrasting with individual access in file systems.

Advantages of DBMS Over File Systems

Efficient Data Retrieval

• When searching for specific data (e.g., train details on IRCTC), using a file system would require downloading large amounts of unnecessary data (e.g., 25 GB), leading to inefficiency.

• In contrast, DBMS allows users to execute simple SQL queries that return only relevant information (e.g., 1 kB), enhancing speed and memory utilization.

Simplified Access Without Metadata Requirements

• Users accessing data via a file system must know metadata such as file names and locations; however, DBMS abstracts this complexity.

• With DBMS, users can query without needing to understand where or how the data is stored, simplifying access significantly.

Concurrency Management

• Concurrency refers to multiple users accessing the same data simultaneously. This is crucial for applications like IRCTC that handle thousands of transactions daily.

• Unlike file systems that may lead to inconsistencies when accessed concurrently by many users, DBMS has protocols ensuring safe concurrent access (e.g., read-read operations are safe).

Conclusion

Concurrency and Security in Database Management Systems

Concurrency Issues

• The write-write problem is a significant issue in concurrency, particularly in database management systems (DBMS). Unlike file systems, DBMS have established protocols to manage concurrency effectively.

Importance of Security

• Security is a critical concern today. It involves ensuring that data access is controlled based on user roles, preventing unauthorized access to sensitive information.

Role-Based Access Control

• In environments like universities, different users (students, faculty, admin) may need varying levels of data access. This necessitates a hierarchical security model known as role-based access control.

• Role-based access means creating distinct roles for users such as students and faculty, each with specific permissions regarding data visibility.

Implementation of Security Protocols

• Websites often implement role-based access controls to restrict information visibility based on user authentication. For example, only authorized personnel can view certain data while general users see limited information.

• File systems lack these hierarchical security measures; they primarily rely on operating system-level password protection without granular control over data accessibility.

Data Redundancy Concerns

• Data redundancy refers to the unnecessary duplication of data within files. For instance, storing the same student record multiple times leads to inefficiencies.

Constraints in DBMS vs. File Systems

• While operating systems prevent duplicate file names, they do not stop content duplication across differently named files. In contrast, DBMS enforce constraints like primary and foreign keys to maintain data integrity and uniqueness.

Conclusion: Superiority of DBMS

• The constraints provided by DBMS ensure that only unique data is stored efficiently. This capability makes them superior to traditional file systems for managing client-server architectures and web applications.