1.The two relation schemes R1 (A, B) and R2 (C, D) has two corresponding relation instances r1 and r2. B from R1 is the foreign key that refers to C in R2. The statement that always holds true if data in r1 and r2 satisfy referential integrity constraints is
πB (r1) – πC (r2) ≠E πB (r1) = πC (r2) πB (r1) – πC (r2) = E πC (r2) – πB (r1) = E
2.The relation R that has x number of tuples is joined with relation S that has y number of tuples. The maximum and minimum sizes of join respectively are
xy and x + y x + y and I x - yI xy and 0 x + y and 0
3.Consider a B+ tree in which order of the internal node is 3 and that of the leaf node is 2. The key values are inserted into this tree in the order given as 10, 3, 6, 8, 4, 2, 1. The order of the internal node is the maximum number of tree pointers in each node and the order of the leaf node is the maximum number of data items that can be stored in it. Assume that the B+ tree is initially empty. As a result of this iteration the maximum number of times leaf nodes would get split up is
2 3 4 5
4.Which one of the following statement is incorrect for the basic ER and relational models?
An attribute of an entity can be composite An attribute of an entity can have more than one value An attribute can have exactly one value or a NULL value in a row of a relational table An attribute can have more than one value in a row of a relational table.
5. Which one of the following statement about B+ trees is correct?
B+ trees are for secondary indexes and B trees are for primary indexes B+ trees are for main memory and B trees are for storing data on disk B+ trees height is independent of the number of records On B+ trees range queries are faster
πB (r1) – πC (r2) ≠E πB (r1) = πC (r2) πB (r1) – πC (r2) = E πC (r2) – πB (r1) = E
2.The relation R that has x number of tuples is joined with relation S that has y number of tuples. The maximum and minimum sizes of join respectively are
xy and x + y x + y and I x - yI xy and 0 x + y and 0
3.Consider a B+ tree in which order of the internal node is 3 and that of the leaf node is 2. The key values are inserted into this tree in the order given as 10, 3, 6, 8, 4, 2, 1. The order of the internal node is the maximum number of tree pointers in each node and the order of the leaf node is the maximum number of data items that can be stored in it. Assume that the B+ tree is initially empty. As a result of this iteration the maximum number of times leaf nodes would get split up is
2 3 4 5
4.Which one of the following statement is incorrect for the basic ER and relational models?
An attribute of an entity can be composite An attribute of an entity can have more than one value An attribute can have exactly one value or a NULL value in a row of a relational table An attribute can have more than one value in a row of a relational table.
5. Which one of the following statement about B+ trees is correct?
B+ trees are for secondary indexes and B trees are for primary indexes B+ trees are for main memory and B trees are for storing data on disk B+ trees height is independent of the number of records On B+ trees range queries are faster
No comments:
Post a Comment