Interesting question on SQL

Question

Consider a database with three relation instances shown below. The primary keys for the Drivers and Cars relation are did and cid respectively and the records are stored in ascending order of these primary keys as given in the tables. No indexing is available in the database.

D: Drivers relation

did	dname	rating	age
22	Karthikeyan	7	25
29	Salman	1	33
31	Boris	8	55
32	Amoldt	8	25
58	Schumacher	10	35
64	Sachin	7	35
71	Senna	10	16
74	Sachin	9	35
85	Rahul	3	25
95	Ralph	3	53

      R: Reserves relation

did	cid	day
22	101	10/10/06
22	102	10/10/06
22	103	08/10/06
22	104	07/10/06
31	102	10/11/06
31	103	06/11/06
31	104	12/11/06
64	101	05/09/06
64	102	08/09/06
74	103	08/09/06

      C: cars relation

cid	cname	colour
101	Renault	blue
102	Renault	red
103	Ferrari	green
104	Jaguar	red

select D.dname
from Drivers D
where D.did in  (
                        select R.did
                        from Cars C, Reserves R
                        where R.cid = C.cid and C.colour = 'red'
                        intersect
                        select R.did
                        from Cars C, Reserves R
                        where R.cid  = C.cid and C.colour = 'green'
                         )

Let n be the number of comparisons performed when the above SQL query is optimally executed. If Binary Search is used to locate a tuple in a relation using primary key, then what is the range of n?

Comments

Does this query print Karthikeyan   Boris?

---

yes.