Data Security. The security of data is low in file based system because, the data is maintained in the flat file s is easily accessible. For Example: Consider the Banking System. The Customer Transaction file has details about the total available balance of all customers. A Customer wants information about his account balance. Thus enforcing security constraints for the entire file or for certain data items are difficult.
Transactional Problems. The File based system approach does not satisfy transaction properties like Atomicity, Consistency, Isolation and Durability properties commonly known as ACID properties. For example: Suppose, in a banking system, a transaction that transfers Rs. If a system crash occurred after the withdrawal of Rs. It means that the transactions should not execute partially but wholly. It is difficult to achieve this property in a file based system. Concurrency problems. When multiple users access the same piece of data at same interval of time then it is called as concurrency of the system.
When two or more users read the data simultaneously there is ll problem, but when they like to update a file simultaneously, it may result in a problem. Let us consider a scenario where in transaction T 1 a user transfers an amout1t from. Account A to B initial value of A is and B is In mean while, another transaction T2, tries to display the sum of account A and B is also executed. In File Processing System, poor data integrity often arises and it becomes very difficult to add new constraints at that time.
For Example : The maximum marks of the student can never be more than Poor data security is the most threatening problem in File Processing System.
There is very less security in File Processing System as anyone can easily modify and change the data stored in the files. All the users must have some restriction of accessing data up to a level.
For Example : If a student can access his data in the college library then he can easily change books issued date. Also he can change his fine detains to zero.
Atomicity is required to save the data values, it means that information is completely entered or canceled at all. Any system may fail at any time and at that time it is desired that data should be in a consistent state. For Example : If you are buying a ticket from railway and you are in the process of money transaction. Suddenly, your internet got disconnected then you may or may not have paid for the ticket. If you have paid then your ticket will be booked and if not then you will not be charged anything.
All the files were grouped based on their categories; the file used to have only related information and each file is named properly. As we can see in the above sample file has Student information. Student files for each class were bundled inside different folders to identify it quickly. Now, if we want to see a specific Student detail from a file, what do we do? We know which file will have the data, we open that file and search for his details. Fine, here we see the files; we can open it and search for it.
But imagine we want to display student details in a UI. For example, let us assume a file for storing addresses of students.
If we make three copies of the address file and store them in three different computers, we say that the data is redundant. If suppose one want to change the address of any students, then the change should be made at all the three computers failing which leads to inconsistent data. In a file processing system, to access data differently we need to have different programs. For example, if you want to access student names from a file, we need a program that does the job.
If you want to view only address of all students from a specific city, then we need different program that does the required job. This list goes endless. Hence, it is difficult to access data. Files are stored in different locations, different formats. Thus they are isolated.
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