NPTEL

Question

Consider a relation R(a,b,c) ordered on a non-key attribute b, and an index is maintained on attribute c. To evaluate the following expression, which is a better order of operation?
                      σ(b=‘abc′∧c=12)(R)

1.First filter tuples u sing index on c and then search for b

2.First search tuples for the given value of b and then use index on c

3.The order of operation does not matter
 
4.Insufficient data to answer

Comments

NO, C is not a primary key.

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@joshi_nitish how you are getting those TC???

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@joshi_nitish not getting your solution properly. can you please explain?

On b it seems clustered indexing, on c it seems secondary indexing.

So clustered would be more efficient.