SOLVED

Multiple Choice Questions: 1)A file is typically partitioned into individual ______ which are the smallest unit of transfer between internal and external memory. a)blocks b)disks c)keys d)lines 2)Which ADT operation(s) on an external file require us to transfer information to/from internal memory? a)removals only b)insertions only c)insertions and removals only d)insertions, removals and retrievals 3)What type of tree is best used for indexing external data? a)B-tree b)binary search tree c)2-3-4 tree d)AVL tree 4)In a binary search tree, if a node has two children, then how many key values does the node itself contain? a)none b)one c)two d)the number may vary 5)Suppose a B-tree of order 5 contains the key values 20, 40, 60 and 70. What happens when we insert the key value 80? a)All 5 key values can reside at the root node. b)The root becomes 80. c)The root becomes 60. d)The root becomes 40. 6)Let N be a node in a B-tree. If N has m subtrees S0, S1, S2, …, Sm–1, and N’s key values are K1, K2, K3, …,  Km–1, then which of the following statements is true? a)All values in subtree S0 are greater than K1. b)All values in subtree S1 are less than K1. c)All values in subtree Sm–2 are greater than Km–2. d)All values in subtree Sm–1 are less than Km–1. 7)In the external version of mergesort, if we begin by performing 16 sorted runs with 1 block each, what is the next step? a)1 sorted run, 16 blocks each b)2 sorted runs, 8 blocks each c)4 sorted runs, 4 blocks each d)8 sorted runs, 2 blocks each 8)The maximum number of records in a B-tree of degree 5 and height 2 is ______. a)10 b)20 c)24 d)30 9)Which statement is true about B-trees? a)Traversals of a table can be done in sorted order more efficiently than a hash table. b)All nodes are children of the root. c)The root node contains either the largest or smallest key value. d)If there are n nodes in the B-tree, then the height of the tree is log2 n. 10)The technique of referencing an employee table with either a Social Security Number or a name as the key value is ______. a)double hashing b)random access c)sequential access d)multiple indexing 11)An index file consists of index records. An index records consists of two parts: a key and a ______. a)hash value b)node c)pointer d)value 12)When we access external data, a location that temporarily stores data between one process and another is called a ______. a)block b)buffer c)file d)record 13)When deleting a key value from a B-tree, what happens if this results in its node becoming empty? a)A new root node must be created. b)A new child node must be created. c)The empty node must merge with another node. d)The empty node must split into two nodes. 14)Which of the following information is not necessary in order to perform (i.e. invoke) a readBlock operation? a)buffer b)file c)block number d)the data contained in the block 15)In the external mergesort algorithm, how many buffers are needed to merge runs? a)one b)two c)three d)four