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