Data is a virtual organizational resource which is an important input in an information system. This data resource is traditionally called the data base. It is from this data base that data is processed and converted into information to satisfy information needs of the organization. Nowadays we find that the internal and external information resources available to organizations are increasing at a rapid rate, due to which data bases are becoming larger and larger in size. At the same time, business environment has forced the business to take quick and right decisions for which database are required to be queried frequently. Queries may be varied, e.g. one manager may be interested to know the names of all those products for which sales in the current year exceed that of the previous year, one may require information on the total amount outstanding, or one may require the list of products having a market share greater than 30 per cent and so on. To correctly process varied types of queries and to ensure fast response time the use of computer – based information systems have become a necessity of any business.
To need the objective of fast retrieval of data, computer – based information system should be able to organize, store and manage data effectively and efficiently. There are two main methods two organize data on computer media, which are known as files and databases.
What is a Database?
Traditionally, different types of information are stored in different places, e.g. product information is stored in a filing cabinet, supplier phone numbers in a card file, order information in a computerized spreadsheet like Ms – Excel, and customer addresses in mailing list. Compiling and updating information from these multiple sources of data turn out to be a very tedious process.
A database is a collection of information in the digital form related to a particular subject or purpose, such as tracking customer orders or maintaining a music collection. If an organizations database is not stored on a computer, or only parts of it are, it may be tracking information from a variety of sources that have to be coordinated and organized. Using a DBMS such as Ms – Access all such information can be managed from a single database file.
Within the file, data is divided into separate storage containers called tables. Table data can be viewed, added, and updated using online forms. An organization can find and retrieve just the data it requires using queries, and analyze or print data in a specific layout using reports. The advantage of storing data in a database is that data are stored only once in a single location, can be viewed from multiple locations, and if updated at a single point, it is automatically updated everywhere it appears.
A database is a collection of records in a structured format. Data in a structured format are easily retrievable for analysis and calculations. It is possible to query data that exist in a structured format. For example, if a manager wants to select the best customer, he need not ask the information systems department for a report on sales figures, but can simply compare the total amounts and customer ID fields for all the records in the sales order database and select the best customer, as shown in table.
|Order ID |Cust ID |Emp ID |Order date |PO |Total | | | | | |number |Amount | |1 |Stop N shop | | | | | |2 |Stop N shop | | | | | |3 |Stop N shop...