Databases Query Optimization question

quinnd6

Join query- theory query optimisation q

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Got a query optimisation q

a relation r(a,b,c) is to be joined to relations S(B,c,d).
The inclusion dependancies R.B subset S.B and
S.c subset R.C
hold.
let IB(in S) = 70 ,
Ic (in R) = 50
let R have 7500 tuples packed on 600 blocks
and
S have 1000 tuples packed on 100 blocks .
let m =101.

What is the output size U of the join R (2 triangles with points facing each other symbol ) S?
What is the Image size?
What are the dominant factors for join and cross product - why are they different?

What happens if s increases as follows Bs = 300 , Ts = 3000?

Ok thats the Q I got.
I think I figured out how to get the output size not sure if Im right though.
From the details above I got
Ib=70
Ic=50
R=7500 tuples in 600 blocks
S= 1000 tuples in 1000 blocks
M=101

output size=(BrTs+BsTr) / Ib Ic
= 600*1000+ 1000 *7500/ 70*50
=600000+ 7500000/ 3500
=8100000/3500=
2314 Blocks

So how do I calculate the image size and what are the dominant factors?

cousin_borat

Are you studying for your repeat exams?

Smoggy

Thats such a none real world question , I have designed enough large scale database as have never done a single calculation like that !.

edit : I have just re read it , this line is a stunner :

What is the output size U of the join R (2 triangles with points facing each other symbol ) S?

:D

quinnd6

yeah I dont know what that symbol is called so I just described what it looks like.