Home » Computer Science
Category Archives: Computer Science
SBM4102 @ Data and Information Management
|Due date:||Week 13|
|Learning outcomes:||[ULO1], [ULO2], [ULO3], [ULO4], [ULO5], [ULO6], [ULO7]|
Read the case study below please
Australian Institute of Music is a music college across the Australia. It provides wide ranges of courses related to music. The top-level management of the college has recently decided to computerise the existing paper-based data to a database in order to keep record of all staff, students, courses, etc. Such database will facilitate saving, restoring, and reporting whenever required and reduced paper consumption in the college. The following describes information that is required to save in the database.
Cost of each course is presented in the table below.
- It should be noted that some courses run for half an hour while others run for an hour. The minimum course time to teach is 30 minutes.
- The college also needs to maintain information about teaching staff. For example, it is required to record which staff teaches which instruments. For example, David teaches singing and piano. Information related to staff includes staff id, name and family, date of birth, phone number, address, and degree. Each staff has a unique ID to ensure easy identification.
- In addition, information related to students is required to maintain in this database. Students has name, postal address, date of birth, and contact phone number. Once a student is joined to the college, he or she can enrol in to interested instruments course. The date and time of the course(s) should be recorded, as well as the duration.
- Furthermore, it is necessary to record which staff member will be taking the course and instrument the course is defined for. Students pay for their courses once the course is finished. It is necessary to record the condition for the course payment and the date paid.
- Another type of information which is required to store is the available instruments in the college stock. This includes the instrument name, manufacture name, quantity or number of each instrument in the stock. The staff may use one or more instrument for teaching purpose.
- At the end of every month, the staff issues invoice statements. An invoice, which has a unique number, is issued for those students who have one or more unpaid courses in the previous month. An invoice, for example, contains date, student information, and total amount due.
YOU NEED TO DO THE FOLLOWINGS
Part-1 Entity-relationship data model
You are required to develop an ER model to represent the information requirements for given case study.
Your ER model must:
- show all necessary entities, attributes and relationships
- show unique identifiers
- show minimum and maximum cardinality.
- show associative entities, if applicable
Some business rules given in the case study may not be clear to you when you read the case study. You may simply make an assumption and then develop your ER model.
You are required to write brief definitions for the entities and attributes in your model. For each entity and attribute in your model, write a sentence to describe the meaning of that entity or attribute.
What you need to should submit
You should submit a Microsoft Word document containing:
- A copy of your entity-relationship model.
- A list of business rules that are apparent from the case study.
- A list of any assumptions that you made with justifications.
Part-II Relational database implementation
You must implement the entity-relationship model based on Assignment 1.
The recommended tool for this assignment is Microsoft Access.
In implementing the ERD provided, you must complete the following tasks:
- Map the ERD into a set of relations in at least Third Normal Form (3NF). You must ensure that your relations meet 3NF. Show your working.
- List all the functional dependencies present in the relation
- Create all the relations in a Microsoft Access database. Consider each attribute in every table and make appropriate choices regarding data types and sizes, indexes, required/not required, and validation rules. Your choices should be appropriate for each attribute and should support data integrity.
- Create relationships as appropriate. Enforce referential integrity for all appropriate relationships in the database.
- Populate the database with sample data. You must include sufficient sample data to test your queries and report(s). You should aim for at least 4-5 rows in every table.
You are required to implement integrity constraints within the database to enforce the following requirements:
- Lesson duration cannot be less than 30 minutes (half hour).
- Cost cannot be negative (but it can be 0).
- Paid must be either yes or no.
- Date paid cannot be in the future.
For invoice statements:
- Statement date must be supplied.
- Statement date cannot be in the future.
- Paid must be either yes or no, it cannot be null.
- Statement total must be supplied.
- Statement total must be greater than 0.
- The payment date must be on or later than the statement date.
Create queries manually using SQL view.
- List details of students who are under 18 years of age.
- Show details of lessons coming up in the next 7 days (if any).
- Show a list of students and the total number of lessons they have had. Show the student ID, family name, given name, and the number of lessons.
- Show details of any student who has had piano lesson.
What you need to should submit
A Microsoft Access database
Tables with sample data
ENTITIES : COURSE, STUDENT, PAYMENT, INSTRUMENT, STAFF, CALSS SCHEDULE
MIGHT BE MORE THEN THIS! PLZ FIND IT
Case Study 2: Solid State Drives
Due Week 6 and worth 130 points
Read the article titled, “Enterprise IT shops now choose SSD storage,” located here and at http://searchsolidstatestorage.techtarget.com/feature/Enterprise-IT-shops-now-choose-SSD-storage.
Use the Internet and Strayer Library to research the benefits and hazards to organizations that use solid-state drive (SSD) storage devices.
CASE STUDY 2: Solid State Drives
According to DeForest, M. R., Call, M., & Syu, M. M. L. (2013), the solid state device is a disc that uses integrated circuit assemblies to store data indefatigably. The disc uses an electronic line compatible with traditional input/output (I/O) that allow surrogate in common applications. An example of such is the SATA Express, an application that is tailor-made to address the SSD technology requirement. The SSD are better compared to electromechanical disks as they can be able to resist physical shock, lower access time, less latency and they run silently. The demerit of SSD is that they are eight times more expensive than the hard disk drives or HDDs. Additionally, SSDs do not display warning signs before failing, and their reliability or longevity, as well as their long term performance is questionable.
Solid State storage is less used in enterprises but the technology is gaining popularity in organizations that are keen to achieve high performance (Hachiya, S., Onagi, T., Ning, S., & Takeuchi, K. 2015, August). The government and NGOs should consider using this technology for their intensive workloads and other huge advantages. The recent legislation on health care may push the state to choose the SSD. The Disabled American Veterans an NGO association with their headquarters in Cold Spring are also considering SSD for their storage especially if the prices are not exorbitant. They have tried the technology in small scale primarily in laptops and it has proved to be effective. The SSD is also said to advance the performance of the database significantly (Min, C., Kim, K., Cho, H., Lee, S. W., & Eom, Y. I. 2012, February). The providers of IT agree that the storage is also useful to those who use colossal amounts of IOPS. Also, it assists those who are actively engaged in E-Commerce especially for those who are preparing to go for their holiday season. It assists them to meet rigorous service-level agreements.
With SATA and SAS interface, as well as form factor compatibility, SSDs have the capacity to be used with the existing disk back-planes, protocols and storage controllers. SSDs do not have moving parts, electromechanical arms, spinning platters, and motors. SSDs boast of greater mean time between failure (MTBF) with innate resistance to vibration, temperature variances and shock. According to parts stress analysis tests, there is a MTBF of 2 million hours for Lightning Write-Intensive SAS SSDs. On the contrary, HHD vendors can typically claim a mean time between failures (MTBF) of 1.2 million hours. Nevertheless, HDD vendors acknowledge the fact that in the real world setting, this figure might be significantly lower than the actual number.
The SSD is also valuable in the university setup and it can handle over a thousand concurrent seasons and detach the system to two data centers for redundancy. It will be more expensive to buy extra hybrid arrays to support the system (Sliwa, 2012). Thus, SSD is more efficient as it refreshes after the user of the system has logout and it doesn’t retain session data. However, there is an increasing pressure on IT managers to deliver greater or improved performance for applications that are data intensive, such as data analytics, data warehousing, virtualization, as well as other applications that can over-utilize HDD solutions (DeForest, M. R., Call, M., & Syu, M. M. L. 2013).
There are several disadvantages and advantages of SSDs. To begin with, the price tag for SSDs per gigabyte is far much greater than HDDs. This means that an upgrade to a similar GB capacity has the potential to incur more cost than the HDDs. Another merit of SSDs is its ability to withstand movement; they are vulnerable to loss of power and magnetic or electrical currents much in the same manner as flash cards. Currently, the number of large capacity SSD models is limited. However, this situation is expected to change dramatically over the course of the next few years. One demerit is of the SSDs is that they have limited write cycle when compared to HDDs. According to the most recent estimates, these write cycles will continue to exist until long after the system is still under use (Hachiya, S., Onagi, T., Ning, S., & Takeuchi, K. 2015, August).. In fact, there is a possibility that some files could utilize write cycles frequently enough that the owner or user is affected. Moreover, despite the fact that SSDs need less power, many SSDs still use more power than the currently existing standard HDDs. This is particularly true when the device is idle. This can cause the particular device to use up energy at a faster rate Min, C., Kim, K., Cho, H., Lee, S. W., & Eom, Y. I. (2012, February).
According to Tanakamaru, S., Yanagihara, Y., & Takeuchi, K. (2012), the SSD as swap enables the government and other agencies to substitute with lower cost solid state storage for higher cost RAM with a diminutive performance brunt. Before any organization considers changing to SSD, they should compare cost over performance. The major benefit of SSD is speed, performance and reliability while its major demerit is its cost which is higher than other storage devices (Zhao, K., Zhao, W., Sun, H., Zhang, X., Zheng, N., & Zhang, T. 2013). Before the company changes to SSD it should consider the following hazards: data destruction, error rates and data recovery. The perception that the disc is safer due to the storage of data on flash memory chips rather than magnetic tapes is overrated. Companies that use SSD have been forced to replace defective SSD media a number of times (DeForest, M. R., Call, M., & Syu, M. M. L. 2013).
The Delaware Health and Social Services should seriously consider SSDs to their organization. The SSD will increase their performance and rate of work. The Delaware Health and Social Services serves a lot of locals. They need a bigger space to store the patient’s information. They are supported by the government hence the cost will not have a major financial impact on the company (Hachiya, S., Onagi, T., Ning, S., & Takeuchi, K. 2015, August). The Disabled American Veterans shouldn’t consider using the SSD as the population they serve is not that demanding in terms of space, speed and performance. The Delaware Health and Social Services is difficult for the computer forensic personnel to consider. The only advantage they have is that they can afford to hire specialists for the forensic examinations. The Disabled American Veterans should consider the aspect in terms of cost. They should not invest heavily in technology that may not be very helpful.
DeForest, M. R., Call, M., & Syu, M. M. L. (2013). U.S. Patent No. 8,423,722. Washington, DC: U.S. Patent and Trademark Office.
Hachiya, S., Onagi, T., Ning, S., & Takeuchi, K. (2015, August). Comprehensive comparison of 3D-TSV integrated solid-state drives (SSDs) with storage class memory and NAND flash memory. In 3D Systems Integration Conference (3DIC), 2015 International (pp. TS6-2). IEEE.
Min, C., Kim, K., Cho, H., Lee, S. W., & Eom, Y. I. (2012, February). SFS: random write considered harmful in solid state drives. In FAST (p. 12).
Sliwa, . (2012) “Enterprise IT Shops now choose SSD Storage”. Retrieved from: http://searchsolidstatestorage.techtarget.com/feature/Enterprise-IT-shops-now-choose-SSD-storage
Tanakamaru, S., Yanagihara, Y., & Takeuchi, K. (2012). Over-10×-extended-lifetime 76%-reduced-error solid-state drives (SSDs) with error-prediction LDPC architecture and error-recovery scheme. In 2012 IEEE International Solid-State Circuits Conference.
Zhao, K., Zhao, W., Sun, H., Zhang, X., Zheng, N., & Zhang, T. (2013). LDPC-in-SSD: making advanced error correction codes work effectively in solid state drives. In Presented as part of the 11th USENIX Conference on File and Storage Technologies (FAST 13) (pp. 243-256).