relational algebra

Consider a selection of the form σA≤100(r)σA≤100(r), where rr is a relation with 1000 tuples. Assume that the attribute values for A among the tuples are uniformly distributed in the interval [0, 500]. Which one of the following options is the best estimate of the number of tuples returned by the given selection query ?

  1. 50
  2. 100
  3. 150
  4. 200
2Comments
shivani @shivani1234
26 Oct 2017 06:51 pm

This question has got more emphasis on keyword "uniformly distributed"
then it means that [0,500] occurs twice to make it 1000 tuples.
So, for σA≤100(r), we have got 200 tuples.

akshat @gaterank
29 Oct 2017 10:02 am

ma'am what the intiall line is stating im confused about that argument