WHAT'S TRENDING

NOUN TMA Portal Login Page - National Open University of Nigeria TMA

Noun TMA Portal login Page link was more visible on the former noun student portal login website ( www.noun.edu.ng ) - if you could remembe...

NOUN Past Questions and Answers - CIT 381 File Processing and Management MARCH/APRIL 2016 EXAMINATION

NATIONAL OPEN UNIVERSITY OF NIGERIA
14-16 AHMADU BELLO WAY, VICTORIA ISLAND LAGOS
MARCH/APRIL 2016 EXAMINATION

SCHOOL OF SCIENCE AND TECHNOLOGY

COURSE CODE: CIT 381
COURSE TITLE: File Processing and Management

Time: 2 hrs
Course Credit Unit: 2

Instruction: Attempt any four (4) questions. Each question carries 17½ marks

1 a. Explain, in writing, what you understand by ”a path name” (5 marks)
The series of directory names, culminating in the file name itself, constitutes a pathname for the file.

b. Write briefly on the following file operations. (1½ mark each = 7½ marks)
i) Creating a File:- When creating a file, a space in the file system must be found for the file and then an entry for the new file must be made in the directory. The directory entry records the name of the file and the location in the file system.
ii) Opening a File:- Before using a file, a process must open it. The purpose of the OPEN call is to allow the system to fetch the attributes and list of secondary storage disk addresses into main memory for rapid access on subsequent calls.
iii) Closing a File:- When all the accesses are finished, the attributes and secondary storage addresses are no longer needed, so the file should be closed to free up internal table space.
iv) Writing a File:- To write a file, a system call is made specifying both the name of the file and the information to be written to the file. Given the name of the file, the system searches the directory to find the location of the file.
v) Reading a File:- This call returns the next entry in an open directory. Formerly, it was
possible to read directories using the usual READ system call, but that approach has the disadvantage of forcing the programmer to know and deal with the internal structure of directories

c. List two (2) types of pathname (5 marks)

Absolute Path name :- With this path name, each file is given a path consist of the path from
the root directory to the file. As an example, the file in the lower lefthand corner of Figure 09 has the pathname User_B/Word/Unit_A/ABC. The slash is used to delimit names in the sequence.

Relative Path name:-

2 a) What types of file extensions will the following contain:

File Type
Extension
A movie in a Video CD
.mpg or .mpeg
A word processed file
.doc or .dot
A file in a Musical CD
.jpg or .jpeg
A Scanned image

A picture taken with a digital camera
.jpg
An Excel file
.xls

b. What is the full meaning of the following acronyms?

S/n Acronym Meaning
i CBIS Computer Based Information System
ii CPU Central Processing Unit
iii RAM Random Access Memory
iv ROM Read Only Memory
v FAT File Allocation Table
vi DVD

Vii
• PDF Portable Document Format
• GIF General Interchange Format
• RTF Rich Text Format
• VFS Virtual File Systems

c. What do you understand by blocking of records? (5½ marks)
Records are the logical unit of access of a structured file, whereas blocks are the unit of I/O with secondary storage. For I/O to be performed, records must be organized as blocks

3 a. What is file management system?(5½ marks)
The file management system, FMS is the subsystem of an operating system that manages the data storage organisation on secondary storage, and provides services to processes related to their access.

b. Write briefly on the following:

(i) Disk quotas:- Multiuser operating systems prevent people from hogging too much disk space by providing a mechanism for enforcing disk quotas.

(ii) Volume:- “a collection of addressable sectors in secondary memory that an OS or application can use for data storage.

c. List three (3) objectives of file management system (6 marks: 2 marks each for any three)
Data management
Protection
Concurrency
Validity

4 a. what are backups? (3½marks):- Backups is the process that involves keeping another copy of the data on some other machine or device so that the copy could be used in case of a system failure.

b. Outline two (2) types of backups you know (4 marks)
Full dump:- simply refers to making a backup copy of the whole disk on another disk or machine.
Incremental dump:- this make a full dump periodically (say monthly or weekly) and to make a daily dump of only those files that have been modified since the last full dump.

c. Explain, in writing, what you understand by user authentication (5 marks)
A major security problem for operating systems is authentication. The protection system depends on the ability to identify the programs and processes currently executing, which in turn depends on the ability to identify each user of the system. The process of identifying users when they log on is called user authentication.

d. How can user authentication be implemented? (5 marks)
User possession (a key or card)
User knowledge (a user identifier and password)
User attributes (fingerprint, retina pattern, or signature).

5. a) List and explain the Logical Components of a file. (5½marks)
A field is the basic element of data
A record is a collection of related fields that can be treated as a unit by some application program
A file is a collection of related records

b) Outline and explain, in writing, any three (3) types of file you know (6 marks)
.exe:- DOS/ Windows program or a DOS/ windows Self Extracting Archive
.dll:- Dynamic Link Library. This is a compiled set of procedures and/or drivers called by another program
.ppt:- A presentation file (for slide shows)
.xls, .123:- Spreadsheet files
.mp3:- Audio Files on both PC and Mac

c) List three (3) File Organisation Criteria (6 marks: 2 marks each for any three)
Short access time
Ease of update
Economy of storage
Simple maintenance
Reliability.

6. a. Differentiate between the following with regards to files operations
(i) Truncating and deleting (1½ marks):- The user may erase some contents of a file but keep its attributes. Rather than forcing the user to delete the file and then recreate it, this operation allows all the attributes to remain unchanged, except the file size. While To delete a file, the directory is searched for the named file. Having found the associated directory entry, the space allocated to the file is released (so it can be reused by other files) and invalidates the directory entry.

(ii) Writing and appending (1½ mark):- To write a file, a system call is made specifying both the name of the file and the information to be written to the file. Given the name of the file, the system searches the directory to find the location of the file. While Appending a file is a restricted form of WRITE call. It can only add data to the end of the file.

(iii) Reading and repositioning (1½ mark):- To read a file, a system call is made that specifies the name of the file and where (in memory) the next block of the file should be putWhile When repositioning a file, the directory is searched for the appropriate entry, and the current file position is set to a given value

(iv) Creating and opening (1½ marks):- When creating a file, a space in the file system must be found for the file and then an entry for the new file must be made in the directory While Before using a file, a process must open it. The purpose of the OPEN call is to allow the system to fetch the attributes and list of secondary storage disk addresses into main memory for rapid access on subsequent calls.

b. List and explain three (3) operations that are to be performed on a directory. (2 marks each for any three = 6 marks)
Create a File:- New files need to be created and added to the directory.
Delete a File:-When a file is no longer needed, we want to remove it from the directory. Only an empty directory can be deleted.
Open a File:-Directories can be read.
Close a File:-When a directory has been read, it should be closed to free up internal table space.

c. List two (2) methods of improving file system performance. (4 marks)
Block Caching:- The most common technique used to reduce disk accesses is the block
cache or buffer cache a cache is a collection of blocks that logically belong on the disk, but are being kept in memory for performance reasons

Reduction in Disk Motion:- Another important technique is to reduce the amount of disk arm motion by putting blocks that are likely to be accessed in sequence close to each
other, preferably in the same cylinder.
SHARE

NOUN Portal Media

Teaching everything about Noun University, sharing all NOUN News & NOUNOnline Portal Guide to easy learning at the National Open University. See How to Apply for National Open University Admission. Study it, Process it and Share it.

  • Image
  • Image
  • Image
  • Image
  • Image
    Blogger Comment
    Facebook Comment

Post a Comment

I would like to learn how did this guide helped you. Share your valuable tips, and comments on the comment form.

P.S: It’s a pleasure to me if you share this guide with your relatives and friends on any social network. That will not only show me how much value you got from this guide but also how much you help others to learn about NOUN Portal

Here's What to Read Today

Recent Posts Widget