1. If the SQL statement SELECT R1.A, R2.B FROM R1, R2 WHERE R1.K = R2.F AND R2.K = 10 is frequently executed, which indexes will prove most useful?

(a) Index on R1.K and index on R2.K

(b) Index on R1.A and index on R2.B

(c) Index on R1.K and index on R2.F

(d) Composite index on (R2.K, R2.F)

2. Which index or storage type is ideal for the query SELECT C1 FROM R1 WHERE C2 BETWEEN 12 AND 20? You may assume most records have values of C2 outside of the range 1220.

(a) Hash index on C2

(b) Clustered B+-tree index on C2

(c) Unclustered B+-tree index on C2

(d) Sorted file on C2

(e) Composite B+-tree index on C1, C2

3. If the SQL statement SELECT C1, C2, C3 FROM T4 WHERE C2=Smith is frequently executed, which column(s) should be considered for indexing based only on the statement itself?

(a) C1 only

(b) C2 only

(c) C3 only

(d) C1 and C2

(e) C1, C2, and C3

4. What can indexes accomplish (compared to having no index)?

(a) Reduce the total number of disk pages read during query processing.

(b) Reduce the total disk seek time during query processing.

(c) Reduce the total number of disk pages written during updates.

(d) a and b

(e) All of the above

5. Which of the following is true?

(a) Primary indexes are always on primary keys

(b) Secondary indexes are always on foreign keys

(c) Primary indexes are always clustered

(d) a and b

(e) none of the above