NIOS Computer Science Chapter 2 – Data Processing Concept Part 2

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Variable and Fixed Length Records

Fixed Length Records:

  • All records in a file have the same number of bytes. Such a file is called a flat file.

  • All records are expected to contain essentially the same quantity of data.

Variable Length Records:

  • Use of variable length records conserves storage space.

  • Quantity of information, of various records in a file.

Data Processing Activities

(a) Collection

  • Data originates in the form of events transaction or some observations.

  • This data is then recorded in some usable form.

  • Data collection is also termed as data capture.

(b) Conversion

  • Converted from its source documents to a form that is more suitable for processing.

  • Data is first codified by assigning identification codes. For example:- An employee may be allotted a code as 52-53-162, his category as A class, etc. It is useful to codify data.

(c) Manipulation

  • Data is collected and converted.

  • It is ready for the manipulation function which converts data into Information.

Sorting

  • Arrangement of data items in a desired sequence.

  • For example: A simple act of sorting the names in alphabetical order gives meaning to a telephone directory. The directory will be practically worthless without sorting.

Calculating

  • Arithmetic manipulation of data is called calculating.

  • Items of recorded data can be added to one another, subtracted, divided or multiplied.

Comparing

  • Compare data is to perform an evaluation in relation to some known measure.

  • Many compare current sales figures.

(d) Storage

Storing

  • Storage is essential for any organised method of processing and re-using data.

  • Storing activity involves storing data and information.

  • Organised manner in order to facilitate the retrieval activity.

Retrieving

  • Retrieve means to recover or find again the stored data or information.

  • Retrieval techniques use data storage devices.

  • Retrieval and comparison of old data gives meaning to current information.

(e) Communication

  • Communication is the process of sharing information.

  • Information is made available to the users.

(f) Reproduction

  • Reproduce is to copy or duplicate data or information.

  • Reproduction activity may be done by hand or by machine.