EXERCISES

1. A fixed disk consists of six platters. The upper surface of the topmost platter and the lower surface of the bottommost platter are not used for recording data. There are 120 tracks on each recording surface. How many of each of the following are there in the disk:
   1. Recording surfaces?
   2. Cylinders?
   3. Tracks per cylinder?
2. A fixed disk has 80 cylinders. The tracks in each cylinder are numbered 0–11. The upper surface of the topmost platter and the lower surface of the bottommost platter are not used for recording data. How many of each of the following are there in the disk:
   1. Recording surfaces?
   2. Platters?
   3. Tracks per recording surface?
3. Consider the B+−tree index, below:
   1. A record has just been added to Cylinder 6, causing a cylinder split. The highest key value on Cylinder 6 is now 2156, the highest key value on Cylinder 20, and the empty reserve cylinder that received half of Cylinder 6's records is now 2348. Update the tree index accordingly.
   2. A record has just been added to Cylinder 10, causing a cylinder split. The highest key value on Cylinder 10 is now 3780, the highest key value on Cylinder 25, and the empty reserve cylinder that received half of Cylinder 10's records is now 3900. Update the tree index accordingly. (Note: this question is intended to be independent of the question in part a. Start each of parts a and b from the figure shown.)