Consider an organization, which has a rented communications channel between two buildings, A and B. They have a set of servers in building A, and wish to back up critical data on an hourly basis to a set of storage drives in building B. They know that the channel has a bandwidth of 10KHz and a signal-to-noise ratio of 20dB.
(i) If their server system generates an average of 45 MB of data each hour, can they use this channel to implement the back up? Explain your answer.
(ii) The organization anticipates a doubling of generated backup requirement in the next year. What advice would you offer in respect of their back up options?
Decibel value and signal-to-noise ratio (SNR) are related as below.
dB = 10 * log(SNR), where log indicates log_base_10.
20 dB = 10 * log_base_10 (SNR)
=> SNR = 10 ^ (20/10) = 10 ^ 2 = 100
Channel bandwidth (B) = 10 KHz
Channel signal-to-noise ratio (SNR) = 100 (i.e. 20 dB)
We can compute channel's capacity (C) by applying Shannon's formula:
C = B * lg(1+SNR), where lg indicates log_base_2.
Channel's capacity (C) = 10 KHz * lg(1+100)
= 10 * lg(101) Kbps
= 10 * 6.6582 Kbps (rounding to ...
Detailed explanations accompany step-by-step solution. In case of question (ii), solution suggests two alternatives.
Database Back up
Please discuss what you believe to be a good backup and crisis management strategy considering the following scenario. Provide a detailed explanation of your choices. Be sure to cite your sources.
You work for a small consulting firm with a sterling reputation for high-quality work and outstanding technical aptitude. You've been assigned as the SQL Server 2000 DBA for an e-commerce project based in coastal Florida. Your client is a well-financed, Internet startup firm focusing on creating an online billing system for large hospitals. As a startup firm, they have limited financial resources and must stringently manage their budget.
There are three database environments for your project: development, staging, and production. The development environment is for the web development to create and test their modules and code. The staging environment is where the various components are assembled and tested as a whole. The production environment is the environment that will eventually be your deliverable to the client and will migrate to become the live web presence for the start up.
The client has approached you in the database server room. She's heard there is severe weather coming to the area that may escalate to hurricane status. She would like you to describe in the detail the backup strategies you've developed for each database environment. She'd really like to know how you can save the company money by applying differing backup and crisis management systems to the varying database environments.View Full Posting Details