NPTEL Week 5 Database Management System Assignment 5 Answers | DBMS Week-5 Quiz Answers 2022 | NPTEL

Summary

In this video, the presenter walks through the solutions for the Week 5 Assignment of a Database Management System course. Key topics include identifying incorrect statements, understanding disk access times, and distinguishing correct options in questions related to database concepts such as URLs, web browsers, RAID configurations, and indexing. The presenter explains complex concepts like rotational delay and disk transfer times with clear calculations, and also clarifies misconceptions around failure times and storage networks. The video is informative for students tackling similar assignments, encouraging them to check the comments for updates and engage with the content.

Takeaways

• 😀 The URL stands for Uniform Resource Locator and a search engine provides links to other websites.
• 😀 The incorrect statement in the first question is option A and D.
• 😀 The correct answer to the third question is option C.
• 😀 The incorrect statements for the fourth question are option B and C regarding slotted page header usage with variable length records.
• 😀 RAID 1 has a higher storage cost than RAID 5, which is the correct answer to the fifth question.
• 😀 In the sixth question, email field is not suitable for indexing due to many null values, making option C correct.
• 😀 For the seventh question, disk access time is the sum of seek time, rotational delay, and transfer time, and the total time required is 61.5 milliseconds (option B).
• 😀 The correct answer to the eighth question is option C.
• 😀 For the ninth question, option B and D are incorrect, with the correct answers being option A and C.
• 😀 In the tenth question, the correct answer is option A. Viewers are encouraged to check the comment section for any changes before final submission.

Q & A

What does URL stand for?

URL stands for Uniform Resource Locator, which is used to identify addresses of web resources.

What is a search engine and how does it function?

A search engine is a website that provides links to other websites based on user queries, helping users find relevant information on the internet.

Which option correctly identifies a web browser in the context of the script?

Option D is correct; a web browser is a software application used to access and navigate websites.

What is a slotted page header and when is it used?

A slotted page header is used in file organization with variable-length records to manage and locate records efficiently within a page.

Why does RAID 1 have a higher storage cost than RAID 5?

RAID 1 duplicates data on multiple disks (mirroring), which increases storage costs, whereas RAID 5 uses parity, providing fault tolerance with less storage overhead.

Which student table attribute is not suitable for indexing and why?

The email attribute is not suitable for indexing because it contains many null values, which reduces the efficiency of indexing.

How is the total disk access time calculated for reading a record?

Total disk access time is calculated by summing the seek time, average rotational delay, and block transfer time. For the given example: seek time (24 ms) + rotational delay (6.25 ms) + transfer time (31.25 ms) = 61.5 ms.

How do you calculate the average rotational delay for a disk?

Average rotational delay is half the time of one full rotation of the disk. For a disk rotating at 4800 rpm, the rotation time is 12.5 ms, so the average delay is 6.25 ms.

What is the difference between a Storage Area Network (SAN) and Network Attached Storage (NAS)?

A Storage Area Network (SAN) connects many disks to multiple servers over a high-speed network, whereas NAS refers to storage devices connected over a regular network providing file-level access.

What does 'Mean Time To Failure' (MTTF) indicate in disk systems?

Mean Time To Failure (MTTF) is the average time a disk operates continuously without experiencing any failure.

What advice is given to students regarding assignment answers?

Students are advised to check the comment section for any updates before final submission, and to mention if they have different answers. They are also encouraged to like and share the video if they found it helpful.