Block Nested Loop Join

Question

Consider a relation R with 2000 records and relation S with 500 records. Size of each record is 5 Byte and block size is 100 Byte, then minimum number of block access that are needed block nested loop join.

I think its answer should be 2525.

Comments

what is the answer?i got 10025

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how you get this please tell your steps.

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Plz check this link..Will be helpful for u @Shubhanshu..

https://gateoverflow.in/76143/block-nested-loop-join

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@Habibkhan Sir, my approach is like this
Relation R has
Block = X = 100
Relation S had
Block = Y = 25
then  min no of block access uing block nested loop join is
min ( X +XY, Y + XY)
so it should be 2525

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2525 is correct

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@Shubhanshu you are calculating block nested join but question says block nested loop join

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2525 seems correct @shubhanshu

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@shubhanshu :- Sorry for consussion. I got confused with nested loop join. 2525 is correct

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@rahul sharma 5   isn't it same  " you are calculating block nested join but question says block nested loop join" ??? so correct answer is 2525.

Answer 1

2525 is the right answer.

Their were many wrong questions in this ace test.

Answer 2

watch this video for concept https://www.youtube.com/watch?v=rT4eI3p3tVk

Here, S is outer relation and R is inner relation. For a minimum number of block accesses, outer relation should be smaller.

Number of records in each block =  (Size of Block)/(Size of Record) = 100B/5B = 20

NR = Total Number of records in R = 2000

BR = Number of blocks in R = 2000/20 = 100

NS = 500

BS = 500/20 =25

Number of total block accesses = BS + BS*BR (for Block nested loop join) = 25 + 25*100 = 2525