File organization, Basic Computer Science

Assignment Help:

File Organization

There are three types of file organization used in practice. Let us consider the example of a dictionary. The dictionary contains listing of English words sorted alphabetically. The top left and right hand corners provide the starting and the ending of each page. Let us assume that the information of the dictionary is stored on a disk. Now suppose, we want to find a word, say, “Computer”. This can be done in the following ways:

    Sequential Access: We start from the first word and check whether or not it is the desired word. We continue checking till the required word is found. This method implies searching the whole file from beginning to end and is known as sequential processing. Time required to locate a specific word will obviously depend on its location from the starting point.

    Indexed Sequential Access: To locate “Computer”, we can also search only the top corner words to first identify which particular page the word belongs to. After knowing the specific page, we can then search sequential till the required word is found. In this method, firstly an index has been searched followed by a complete sequential search. This method is known as indexed sequential method and is much faster compared to sequential method and is very commonly used in practice.

    Random Access: Suppose each word is assigned a specific sequence number and “Computer” was 25th from the beginning. Then we could go directly to the 25th location on the disk without any searching. This type of processing is known as Random Access and the response in this method will be very fast. However, the concept of allocating a unique number, to each data item, becomes difficult as the complexity increases.


Related Discussions:- File organization

Transaction-based model, Transaction-based model: Here,  the pricing i...

Transaction-based model: Here,  the pricing is based on providing a committed business service, for ex, processing payroll for a global company as part of HR offering and this

Languages, Languages The language is a program containing rules and...

Languages The language is a program containing rules and guidelines to help us in making programs. There are various languages like C, Basic, COBOL, PASCAL, FORTRAN etc. Th

Twisted pair cable, what are daily uses of twisted pair cable in network

what are daily uses of twisted pair cable in network

Digital video disks, Digital Video Disks: DVD stands for Digital Video...

Digital Video Disks: DVD stands for Digital Video Disks or Digital Versatile Disks. A DVD stores much more data than a CD-ROM. Its capacities are 4.7GB, 8.5GB, and 20GB etc. T

Transmission media, TRANSMISSION MEDIA: When we speak of transmission ...

TRANSMISSION MEDIA: When we speak of transmission media, we usually mean a mix of physical lines ranging from wire pairs to cable, and over the air transmission media, such as

Php, Which of the following is NOT a type of SQL constraint?

Which of the following is NOT a type of SQL constraint?

Linux Calculator in Java, Hello, Could you create a linux calculator using ...

Hello, Could you create a linux calculator using very basic java code (not complex, because I am a novice java coder). It should be called into the terminal for interaction. Thank

Define server clustering, Question 1 Discuss the impacts of disaster faced...

Question 1 Discuss the impacts of disaster faced by the organization Question 2 Explains the steps involved in disaster recovery planning Question 3 What do you mean by

What is a Process and process mangemen in operating system? , A process is ...

A process is a chronological program in execution. The constituents of a process are the following: • The object program to be executed ( described the program text in UNIX) • Th

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd