Question

A single species of fish, the three-spined spinyback, once inhabited a large lake. At some point in the lake's history, lava flowed from a nearby volcano into the lake cutting it into three completely isolated mini-lakes. Despite the heat from the lava, a few individuals from the original population of spinyback survive in each mini-lake. Three million years later, a researcher finds that each mini-lake is inhabited by its own species of spinyback. Which of the following figures MOST closely reflects how the three species of spiny back are related to one another? a.tree H b.tree K c. tree M e. tree L

Answer 1

Tree H

Step-by-step explanation:

It's a self-balancing search tree. In most of the other self-balancing search trees, it is assumed that everything is in main memory. To understand the use of B-Trees, we must think of the huge amount of data that cannot fit in main memory. When the number of keys is high, the data is read from disk in the form of blocks. Disk access time is very high compared to main memory access time. The main idea of using B-Trees is to reduce the number of disk accesses. Most of the tree operations require O(h) disk accesses where h is the height of the tree. B-tree is a fat tree. The height of B-Trees is kept low by putting maximum possible keys in a B-Tree node. Generally, a B-Tree node size is kept equal to the disk block size. Since h is low for B-Tree, total disk accesses for most of the operations are reduced significantly compared to balanced Binary Search Trees.