Databases Multiple granularity

Question

Answer 1

Real all pages in file1

This means that we are accessing all the records under all the pages$\left (P_{1}, P_{2}, P_{3},......, P_{1000} \right )$ under FILE1. For locking records protocol first need to lock the ancestors in IS mode. Protocol will lock D in IS mode then F1 in IS mode then it will finally lock  $\left (P_{1}, P_{2}, P_{3},......, P_{1000} \right )$ in IS and shared lock to the records.

Hence option A is correct.

 

Comments

answer given is C. If anyone comes up with correction please do comment.

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Is this valid for GATE 2019?

I mean is it there in the syllabus? I see various test series asking these questions as well.

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Manoja Rajalakshmi A can you explain?

Answer 2

We need to read all the pages from file F1.

So we must use shared lock on F1.

But we are particularly choosing between F1 and F2 then we have to set IS on D.

Hence Option C is correct choice.

Answer 3

Option (C) is answer as on F1 shared lock(S) will be applied and on D intension shared lock(IS) will be applied as D is ascendant of F1.