Data Structures | B and B+ Trees | Question 3

B+ trees are preferred to binary trees in databases because (GATE CS 2000)
(A) Disk capacities are greater than memory capacities
(B) Disk access is much slower than memory access
(C) Disk data transfer rates are much less than memory data transfer rates
(D) Disks are more reliable than memory

Answer: (B)
Explanation: Disk access is slow and  B+ Tree provide search in less number of disk hits. This is primarily because unlike binary search trees, B+ trees have very high fanout (typically on the order of 100 or more), which reduces the number of I/O operations required to find an element in the tree.
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