Assignment 1-
1. Describe the following disk concepts or components.
a. Platter and recording surface.
b. Track.
c. Cylinder.
d. Read/write head.
e. Access-arm mechanism.
2. Describe the four steps in the transfer of data from disk to primary memory.
3. What is an index? Compare the concept of the index in a book to an index in an information system.
4. What is an indexed-sequential file?
5. Describe how a direct search works using a B+-tree index.
6. Answer the following general questions about indexes:
a. Can an index be built over a non-unique field?
b. Can an index be built over a field if the file is not stored in sequence by that field?
c. Can an index be built over a combination of fields as well as over a single field?
d. Is there a limit to the number of indexes that can be built for a file?
e. How is an index affected when a change is made to a file? Does every change to a file affect every one of its indexes?
f. Can an index be used to achieve sequential access? Explain
7. Describe how a direct search works in a hashed file using the division-remainder method of hashing.
8. What is physical database design?
9. Describe why physical database design is necessary.
Assignment 2-
1. Consider the following relational database that Best Airlines uses to keep track of Its mechanics. their skills. and their airport locations. Mechanic number (MECHNUM). airport name (AIRNAME). and skill number are all unique fields. SIZE is an airport's size in acres. SKILLCAT is a skill category, such as an engine skill, wing skill, tire skill. etc. YEARQUAL is the year that a mechanic first qualified in a particular skill: PROFRATE is the mechanic's proficiency rating in a particular skill.
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MECHANIC Table
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MECHNUM
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MECHNAME
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AGE
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SALARY
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AIRNAME
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AIRPORT Table
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AIRNAME
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CITY
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STATE
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SIZE
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YEAROPENED
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SKILL Table
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SKILLNUM
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SKILLNAME
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SKILLCAT
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QUALIFICATION Table
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MECHNUM
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SKILLNUM
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YEARQUAL
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PROFRATE
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Write SQL SELECT commands to answer the following queries.
a. List the names and ages of all the mechanics.
b. List the airports in California that are at least 20 acres in size and have been open since 1935 Order the results from smallest to largest airport.
c. List the airports in California that are at least 20 acres in size or have been open since 1935.
d. Find the average size of the airports in California that have been open since 1935.
Assignment 3-
Project: Database Design
You just took a job with a University and have been asked to track some information about the courses they offer. The previous employee was using a spreadsheet to track this information. The University is expanding from three classes to three hundred classes. Enrollment is expected to increase from around 20 students to 5,000. Your supervisors are not very tech savvy and they simply ask you to continue maintaining the spreadsheet. You feel that developing a database is a better solution.
Here is a link to the spreadsheet currently in use
Write a proposal for the new database design to include:
• An executive summary for the database project
• Develop main project details
o Explain the issues that exist with maintaining the data in its current form.
o Explain the process of migrating the data in its current form to a well formed data model by highlighting the following in detail:
- Identify required attributes that need to be tracked
- Identify functional dependencies
- Show the redesign in 1NF, 2NF, and 3NF (similar to figures 7.29, 7.31, 7.33)
Explain the project benefits of the data in its new form.
Create the E-R diagram of your relational tables using MySQL Workbench and include in proposal.
Propose some additional data items, which you believe may be beneficial to the University if tracked in your database (i.e. Descriptions, more info about the instructors and students, departments, etc). Describe the steps required to implement these additions.
Identify project risks
In addition to the proposal, in a separate file submit:
o Provide the SQL statement required to create at least one of your tables.
o Provide the SQL statement required to delete at least one of your tables.
o Provide the SQL statement required to create a view which includes Course #, Course Name, Time, and Days only.
o Identify at least one index, which you believe would improve performance. Explain your choice.