Write about data structures IN COMPUTERS
Data : Basic facts about the activities of a business. It is generally in the form of names and numbers, time and date, weights, prices, product names, roll numbers, account numbers, customer numbers etc.
Information : It is the set of data which has been converted or organized into a more useful or intelligible form.
Data Processing : The term used for process of collecting all items of data together to produce meaningful information. It is mostly associated with business and commercial work such as banks, insurance companies, schools and so on. It involves scientific data processing. Can be done in many ways viz., manually, semi-manual, mechanically and electronically.
Electronic Data Processing : Data is basically of two types – qualitative data and quantitative data. Qualitative data denotes the qualities as colour, state, length etc., Both types of data need to be recorded before they are processed to get meaningful and required output.
Fields : Raw Data exists in the form of ‘fields’. Field is the smallest unit of data which usually represents/refers to a single property of an entity. Eg. Salary of an employee, roll number of a student etc.
Records : Group of fields pertaining to single item of reference such as marks in various subjects secured by a student. It is the collection of related elementary terms. A record can be given a name by which the entire collection can be referred to. Eg. Bio-data of an employee.
File : It is a systematized self-contained collection of records or information. The files can be termed as master files which hold data of semi-permanent nature, transaction files which are purely temporary and are being updated continuously.
Elements of a computer file : A file consists of a number of records. Each record is made up of a number of fields and each field consists of a number of characters.
Database : Database is a single organized collection of instructed data stored with a minimum of duplication of data items. This is common to all users of the system but is independent of programmes which use the data. It requires being stored on large-capacity direct-access devices. The customer data of bank is a database, the accounts details of the customers of a bank is a database. Database management is an important task of an organisation. The processed data through database management systems provide more valuable and reliable information to top management that enables decision making in framing policies and adoption various strategies and approaches in business development. Thus database serves multiple applications and users.
Database management systems / Relational Database Management Systems etc., evolved for the purpose of managing data. DBMS is a set of programmes that allow users to access and modify a collection of inter-related files. It provides user with an abstract view of the data. The programmes are used to define, construct and manipulate a database. A database in DBMS is a collection of interrelated data stored together which allows multiple users to access it simultaneously maintaining its consistency and integrity. The use of DBMS reduces data redundancy and allows adhoc or unplanned querying on data.
Relational data model is one of the models in DBMS. In this model the database can be represented in a simple collection of two dimensional tables otherwise known as the Relational Database Management System (RDBMS). Today RDBMS is popular worldwide. It represents and processes data in the form of tables called relations. The columns of the table are called attributes and rows are called tuples. RDBMS uses SQL (Structured Query Language) for data manipulation. Oracle we use in our Bank is an RDBMS. The data is basically arranged in rows and columns which is easier to manipulate and process. Data is retrieved efficiently and fast through the use of indexes. It is very flexible.
