B+Trees

Consider a B+-tree in which the maximum number of keys in a node is 5. What is the minimum number of keys in any non-root node?

• 1

• 2

• 3

• 4

Which one of the following is a key factor for preferring B-trees to binary search trees for indexing database relations?

• Database relations have a large number of records

• Database relations are sorted on the primary key

• B-trees require less memory than binary search trees

• Data transfer form disks is in blocks.

B+ trees are preferred to binary trees in databases because

• Disk capacities are greater than memory capacities

• Disk access is much slower than memory access

• Disk data transfer rates are much less than memory data transfer rates

• Disks are more reliable than memory.

Which of the following is FALSE about B/B+ tree

• B/B+ trees grow upward while Binary Search Trees grow downward

• Time complexity of search operation in B/B+ tree is better than Red Black Trees in general.

• Number of child pointers in a B/B+ tree node is always equals to number of keys in it plus one.

• A B/B+ tree is defined by a term minimum degree. And minimum degree depends on hard disk block size, key and address sizes.

A B-tree of order 4 is built from scratch by 10 successive insertions. What is the maximum number of node splitting operations that may take place?

• 3

• 4

• 5

• 6

The order of a leaf node in a tree B+ ? is the maximum number of (value, data record pointer) pairs it can hold. Given that the block size is 1K bytes, data record pointer is 7 bytes long, the value field is 9 bytes long and a block pointer is 6 bytes long, what is the order of the leaf node?

• 62

• 63

• 64

• 65

The order of an internal node in a B+ tree index is the maximum number of children it can have. Suppose that a child pointer takes 6 bytes, the search field value takes 14 bytes, and the block size is 512 bytes. What is the order of the internal node?

• 24

• 25

• 26

• 27

A B+ -tree index is to be built on the Name attribute of the relation STUDENT. Assume that all student names are of length 8 bytes, disk block are size 512 bytes, and index pointers are of size 4 bytes. Given this scenario, what would be the best choice of the degree (i.e. the number of pointers per node) of the B+ -tree?

• 16

• 42

• 43

• 44

Consider B+ tree in which the search key is 12 bytes long, block size is 1024 bytes, record pointer is 10 bytes long and block pointer is 8 bytes long. The maximum number of keys that can be accommodated in each non-leaf node of the tree is

• 49

• 50

• 51

• 52

A B-Tree used as an index for a large database table has four levels including the root node. If a new key is inserted in this index, then the maximum number of nodes that could be newly created in the process are:

• 5

• 4

• 3

• 2