Organizing Data in a Traditional File Environment
Computer systems organize data in a hierarchy that begins with bits and bytes and progresses to more complex groupings of data:
- Fields: Group of characters, words, or a complete number
- Records: Group of related fields, describes an entity (a person, place or thing about which information must be kept - each characteristic of an entity is an attribute
- File: Group of records of the same type
- Database: Group of related files
Figure 6-1
A computer system organizes data in a hierarchy that starts with the bit, which represents either a 0 or a 1. Bits can be grouped to form a byte to represent one character, number, or symbol. Bytes can be grouped to form a field, and related fields can be grouped to form a record. Related records can be collected to form a file, and related files can be organized into a database. |
In most organizations, the traditional approach to information processing meant that databases and other systems tended to grow independently without a company-wide plan. Accounting, finance, manufacturing, human resources, and sales and marketing all developed their own systems and data files.
Figure 6-2
|
Problems resulting from the traditional file environment include:
- Data redundancy: duplicate data in multiple files, leading to data inconsistency, different values used for the same attribute
- Program-data dependency: Changes in programs requiring changes to the data
- Lack of flexibility
- Poor security
- Lack of data sharing
In earlier days, data was stored manually, using pen and paper but after computer was discovered, the same task could be done by using files. A computer File is a resource which uniquely records data, in a storage device in a computer. There are various formats in which data can be stored. e.g. Text files can be stored in .txt format while pictures can be stored in .png format etc.
In case of computer files, data about data (metadata) can be stored in different lines, separated by spaces, commas or tab to resemble tables. Each file is placed in relevant folders for the ease of access. This can be understood from the screenshot of Notepad below. For a school named GeeksforGeeks, having classes 1 to 5, the data can be stored in the file system in the following way.
Note –
Here, the school GeeksforGeeks has
several classes, depicted through folders (Geeks of class 1, Geeks of class 2 etc.). The folders have files which carry the details of students (All Geeks.txt). The details are stored in tabular fashion, using spaces.
File Processing System :
In Computer Science, File Processing System (FPS) is a way of storing, retrieving and manipulating data which is present in various files.
Files are used to store various documents. All files are grouped based on their categories. The file names are very related to each other and arranged properly to easily access the files. In file processing system, if one needs to insert, delete, modify, store or update data, one must know the entire hierarchy of the files.
Advantages of File Processing System :
- Cost friendly –
There is a very minimal to no set up and usage fee for File Processing System. (In most cases, free tools are inbuilt in computers.)
- Easy to use –
File systems require very basic learning and understanding, hence, can be easily used.
- High scalability –
One can very easily switch from smaller to larger files as per his needs.
Disadvantages of File Processing System :
- Slow access time –
Direct access of files is very difficult and one needs to know the entire hierarchy of folders to get to a specific file. This involves a lot of time.
- Presence of redundant data –
The same data can be present in two or more files which takes up more disc space.
- Inconsistent Data –
Due to data redundancy, same data stored at different places might not match to each other.
- Data Integrity Problems
–
The data present in the database should be consistent and correct. To achieve this, the data should must satisfy certain constraints.
- Difficulty in recovery of corrupt data –
Recovery or backup of lost and corrupt data is nearly impossible in case of File Processing System.
- Lack of Atomicity –
Operations performed in the database must be atomic i.e. either the operation takes place as a whole or does not take place at all.
- Problem in Concurrent Access –
When a number of users operates on a common data in database at the same time then anomalies arise, due to lack of concurrency control. - Unauthorized Access –
Anyone who gets access to the file can read or modify the data.
Note –
Database
Management System (DBMS) is used to eliminate the disadvantages of the FPS.