Exercise 8: MA.Hashing Design
Consider relation Person(name,gender,age) ...
pQ |
Query Type Q |
0.5 |
select name from Person
where gender=X and age=Y |
0.25 |
select age from Person
where name=X |
0.25 |
select name from Person
where gender=X |
Assume that all other query types have pQ=0.
Design a choice vector to minimise average selection cost.
|