615 views
1 votes
1 votes
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

Please log in or register to answer this question.

Related questions

1 votes
1 votes
0 answers
4
gulsanchouhan asked Sep 28, 2017
334 views
Which of the following can be described as a programming model used to develop applications processing massive amounts of data in a distributed and/or parallel manner?1. ...