Case Study:
You are hired as a DBA for a medium size online retailer company “Quick Sale”. The company sells several products, such as computer hardware and software, music, clothing, and tools. The company maintains information about these products, such as product identification numbers, the category into which the product falls, orders information, the supplier, the availability status of the product, a list price, etc. Inventory information is also recorded for all products, including the warehouse where the product is available and the quantity on hand. Customer information is also tracked.
The database design is complete (see ERD below) and you will be provided with the script to upload all necessary data in your VM database. The owners of the tables are user sh and user oe.
The “Quick Sale” company has number of employees working in several departments: Sales, Marketing, Inventory, Customer Service, HR, etc. They need to have different access rights to the tables in the database, based on their job description.
Task:
Your task is to implement DBA requirements specified below using your Virtual Machine provided for the module and describe your solutions for potential DBA problems as specified in the Problem-solving requirements.
DBA requirements:
1.You are required to create 2 tablespaces to store data needed for two different applications with different requirements:
a) First tablespace inv_tsp, will be required to store extra inventory information. This will be for a transactional type of application where every day a large amount of data (around 10Mb) will be entered into tables stored in inv_tsp tablespace. That data also will be updatable on a regular basis.
b) Second tablespace dw_tsp will be used for a data warehousing application with a large data (120Mb) loaded at the beginning and rarely updated.
You are required to create both tablespaces in your database, deciding on the best properties to be used for each tablespeace. You must provide SQL command for each tablespace creation, a screenshot of successful execution of that SQL command and explanation on why you made those choices of tablespaces properties and their values for both tablespaces. What are the benefits, and drawbacks of your choices.
[Up to 10 marks]
2.You are required to create several new users with the following login requirements:
a)Two users for the Customer Service department and one user for the Inventory department. Default tablespace for all users should be inv_tsp and temporary tablespace should be set to temp.
b)All of the above users should have unique usernames and passwords. Password should be at least 8 characters long and users should not be allowed to have a password that is shorter than 8 characters. There shouldn’t be any other enforcement on the password.
c)The users should be forced to change their passwords on their first login, then every 6 months and not allowed to reuse the same password.
d)If during the login they specified their password incorrectly 3 times, the account should be locked for 30 hours.
e)All new users should be allowed to leave their session without interacting with it for no more than 15 min.
Make sure you include an explanation on how these requirements are implemented, possible alternatives, their benefits and drawbacks. Please provide in your report the usernames and passwords for all users created. [Up to 15 marks]
3.New users should have the following access rights:
a)All of the above users should be able to login to the database.
b)Two users for the Customer Service department should have Read/Only access to PRODUCT_INFORMATION, PRODUCT_DESCRIPTIONS, ORDERS, ORDER_ITEMS and CUSTOMERS tables, owned by user oe.
c)Customer Service users should be able to easily query information about all orders for a particular customer based on the customer id. (Remember, Customer service users might not be experienced SQL developers, so they will not be able to create a complex SQL statement with joins, etc. You need to simplify this task for them).
d)The user for the Inventory department should have Read/Write access to the tables: INVENTORIES and WAREHOUSES as well as Read/Only access to ORDERS, ORDER_ITEMS and CUSTOMERS tables, owned by user oe.
e)The user for the Inventory department should also be allowed to create new tables and new views. Make sure you include an explanation on how these requirements are implemented. [Up to 15 marks]
4.The sh user must be able to run a report with the information about all products sold for a particular customer, based on the provided customer id.
You need to implement the best way for this user to produce such reports. The output should include customer id and customer name as well as information about the products that were sold to this customer- product id, product name, quantity sold, and amount sold.
You need to include a rationale for your implementation discussing alternatives, their benefits and drawbacks. Please provide in your report screenshots of sh user successfully running the above report for a particular customer. [Up to 10 marks]
Problem solving requirements:
5.If you accidently dropped an important schema (for example, hr) in your database, discuss the best functionality to use in order to recover it quickly and safely. Provide an explanation of the steps needed to recover data including the SQL commands for each step. [Up to 10 marks]
6.Your users are reporting “ORA-1555: Snapshot too old” errors. What might be the cause of this? Explain what you need to do in order to solve this issue. [Up to 10 marks]
7.Explain the difference between a hot backup and a cold backup and the benefits associated with each. [Up to 10 marks]
8.Discuss how different database failures can impact a business, including the financial costs, and what can be done to minimise the downtime cost. To illustrate your point, find a real-life example, based on your research, of the financial costs suffered by a company due to an Oracle systems failure; what lessons were learnt and what actions were taken to prevent future problems. [Up to 15 marks]
