2. Consider a file currently consisting of 100 blocks. Assume that the file-control block (and the index block, in the case of indexed allocation) is already in memory. Calculate how many disk I/O operations are required for contiguous, linked, and indexed (single-level) allocation strategies, if, for one block, the following conditions hold. In the contiguous-allocation case, assume that there is no room to grow at the beginning but there is room to grow at the end. Also assume that the block information to be added is stored in memory. a) The block is added at the beginning. b) The block is added in the middle. c) The block is added at the end. d) The block is removed from the beginning. e) The block is removed from the middle. f) The block is removed from the end. note: this is full a question that need to be answered. there is no more extra info about this question.

2. Consider a file currently consisting of 100 blocks. Assume that the file-control block (and the index block, in the case of indexed allocation) is already in memory. Calculate how many disk I/O operations are required for contiguous, linked, and indexed (single-level) allocation strategies, if, for one block, the following conditions hold. In the contiguous-allocation case, assume that there is no room to grow at the beginning but there is room to grow at the end. Also assume that the block information to be added is stored in memory. a) The block is added at the beginning. b) The block is added in the middle. c) The block is added at the end. d) The block is removed from the beginning. e) The block is removed from the middle. f) The block is removed from the end. note: this is full a question that need to be answered. there is no more extra info about this question.

Database System Concepts

7th Edition

ISBN:9780078022159

Author:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Publisher:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Chapter1: Introduction

Section: Chapter Questions

Problem 1PE

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A disk has a capacity of two tera-byte size. Say the file system uses a multi-level inode structure for locating the data blocks of afile.The inode stores pointers to data blocks, including a single indirect block, a double indirect block, and several direct blocks in the 64 B of available space.Now, it is given that the disk has a block size of 512 B. The maximum file size that can be stored in such a file system in MB (round off upto 2 decimal places).
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Consider a file system that uses inodes to represent files. Disk blocks are 8 KB in size, and a pointer to a disk block requires 8 bytes. This file system has 12 direct disk blocks, as well as 1 single and 1 double indirect disk blocks. What is the maximum size of a file that can be stored in this file system in GBs (round to the nearest integer)?
Assume that a virtual memory is managed using a buffer pool. The buffer pool contains five buffersand each buffer stores one block of data. Memory accesses are bydiskblock ID. Assume thefollowing series of memory accesses takes place: 5 2 5 12 3 6 5 9 3 2 4 1 5 9 8 15 3 7 2 5 9 10 4 6 8 5 For each of the following buffer pool replacement strategies, show the contents of the buffer poolat the end of the series, and indicate how many times a block was found in the buffer pool (insteadof being readinto memory). Assume that the buffer pool is initially empty a.First in, first out. b.Least frequently used (with counts kept only for blocks currently in memory, counts for a pageare lost when that page is removed, and the oldest item with smallestcount is removed whenthere is a tie). c.Least frequently used (with counts kept for all blocks, and the oldest item with the smallestcount is removed when there is a tie). d.Least recently used.
Assume that a virtual memory is managed using a buffer pool. The buffer pool contains five buffersand each buffer stores one block of data. Memory accesses are bydiskblock ID. Assume thefollowing series of memory accesses takes place: 5 2 5 12 3 6 5 9 3 2 4 1 5 9 8 15 3 7 2 5 9 10 4 6 8 5 For each of the following buffer pool replacement strategies, show the contents of the buffer poolat the end of the series, and indicate how many times a block was found in the buffer pool (insteadof being readinto memory). Assume that the buffer pool is initially empty b.Least frequently used (with counts kept only for blocks currently in memory, counts for a pageare lost when that page is removed, and the oldest item with smallestcount is removed whenthere is a tie). c.Least frequently used (with counts kept for all blocks, and the oldest item with the smallestcount is removed when there is a tie).
Suppose a disk has N cylinders, numbered from 0 to P. At some time, the disk arm is at cylinder X, and there is a queue of disk access requests for cylinders R1, R2, R3, R4. Explain which Disk scheduling algorithm should be the best to be used between the following a) FIFO b) CSCAN c) SSTF d) FSCAN e) CLOOK N: B • • Choose any acceptable numeric numbers for N, P, X, R1, R2, R3 and R4 • • Plagiarism Will be penalized heavily
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2. Assume you are given a function of void my_compress (void *args), which can compress the file. Write a concurrent version of the compression using pthread library. Create very large file, divide the file into equal chunks (say n) and allocate the compression work to n threads. Then assemble the result of each process and output it. You will have an input data file called source.txt, and you need to generate an output compressed data file called destination.txt.
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