Suppose You Are Given The James River Jewelry Database Desig ✓ Solved

Suppose You Are Given The James River Jewelry Database Design As Follo

Suppose you are given the James River Jewelry database design as follows: CUSTOMER ( CustomerID , LastName, FirstName, Phone, Email) PURCHASE ( InvoiceNumber , Date, PreTaxAmount, CustomerID ) PURCHASE_ITEM ( InvoiceNumber , ItemNumber , RetailPrice) ITEM ( ItemNumber , Description, Cost, ArtistName) OWNER ( OwnerID , Name, Phone, Email, AmountOwed) JEWELRY_ITEM ( ItemNumber , DateReceived, DateSold, NegotiatedSalesPrice, ActualSalesPrice, CommissionPercentage, OwnerID ) where CustomerID in PURCHASE must exist in CustomerID in CUSTOMER InvoiceNumber in PURCHASE_ITEM must exist in InvoiceNumber in PURCHASE ItemNumber in PURCHASE_ITEM must exist in ItemNumber in ITEM OwnerID in JEWELRY_ITEM must exist in OwnerID in OWNER ItemNumber in JEWELRY_ITEM must exist in ItemNumber in ITEM The OWNER and JEWELRY_ITEM tables are used to record data and maintain owner data about jewelry accepted on consignment.

JEWELRY_ITEM (which is a subtype of ITEM - note the referential integrity constraint) is used to record the negotiated sales price, the commission percentage, and the actual sales price for each item of consigned jewelry. Assume that office personnel at James River Jewelry use a database application to record consignment data. When an item is received on consignment, owner data are stored in OWNER if the owner is new; otherwise existing owner data are used. New ITEM and JEWELRY_ITEM rows are created. In ITEM, ItemNumber and Description are recorded, Cost is set to $0.00, and if there is an artist associated with the piece, ArtistName is entered.

For JEWELRY_ITEM, data are stored for all columns except DateSold and ActualSalesPrice. James River Jewelry personnel refer to these actions as Acceptance Transactions. Later, if the jewelry item does not sell, the NegotiatedSalesPrice and CommissionPercentage values may be reduced. This is called a Price Adjustment Transaction. Finally, when an item sells, the DateSold and ActualSalesPrice fields for the item are given values, and the AmountOwed value in OWNER is updated by increasing AmountOwed by the owner's percentage of the ActualSalesPrice value.

This third transaction is called a Sales Transaction. Suppose James River Jewelry identifies three groups of users: managers, administrative personnel, and system administrators. Suppose further that managers and administrative personnel can perform Acceptance Transactions and Sales Transactions, but only managers can perform Price Adjustment Transactions. James River Jewelry has developed the following procedure for backup and recovery. The company backs up the database from the server to a second computer on its network each night. Once a month, it copies the database to a CD and stores it at a manager’s house.

It keeps paper records of all services provided for an entire year. If it ever loses its database, it plans to restore it from a backup and reprocess all service requests. Which of the three application transactions must be made atomic (e.g., specify transaction boundaries) to prevent possible lost update? Why and why not? Describe processing rights that you think would be appropriate for the identified three groups of company users.

Comment on the company’s strategy on DB backup and recovery. Describe any changes you think the company should make to its current backup and recovery scheme.

Paper For Above Instructions

The James River Jewelry database design includes several important tables and structures that hold data related to customers, purchases, items, owners, and jewelry items received on consignment. In order to manage transactions effectively and maintain data integrity, it is essential to determine which transactions should be made atomic to prevent possible lost updates or inconsistencies within the database.

Firstly, among the three types of transactions defined—Acceptance Transactions, Price Adjustment Transactions, and Sales Transactions—the Acceptance Transactions and Sales Transactions should be made atomic. Acceptance Transactions involve creating new records in both the ITEM and JEWELRY_ITEM tables, as well as potentially updating the OWNER table if it involves a new owner. These actions form a cohesive unit; if any part of this action fails or is interrupted, the entire process risks leaving the database in an inconsistent state. For example, if a new item is recorded but related owner data is not, it could lead to orphaned records and challenge data integrity. Therefore, treating this transaction as atomic ensures that either all parts of the transaction complete successfully, or none do, maintaining the overall integrity of the data.

Similarly, Sales Transactions also must be atomic. This type of transaction updates the JEWELRY_ITEM table (filling in the DateSold and ActualSalesPrice fields) and modifies the OWNER table (updating the AmountOwed). This transaction significantly impacts the business's financial records; therefore, it is critical that it is processed as a complete unit to prevent scenarios where a sale is recorded without the corresponding updates to owner data, resulting in financial discrepancies.

On the other hand, Price Adjustment Transactions may not need to be atomic to the same extent. Although they are important, the failure of a price adjustment would not put the database into a state of greater inconsistency than if no adjustment had been made. Consequently, making them non-atomic might be acceptable if sufficient logging is in place; however, managers should still ensure there is a rollback mechanism to revert changes made during a price adjustment attempt in case of failure.

Next, regarding processing rights for the different groups of users identified—managers, administrative personnel, and system administrators—appropriate roles can be assigned based on the criticality of the transaction types and the need for data integrity. Managers, holding the level of responsibility for strategic decisions and oversight, should have full access rights, allowing them to conduct Acceptance Transactions, Sales Transactions, and Price Adjustment Transactions. Administrative personnel can be granted access to Acceptance and Sales Transactions, but not to the Price Adjustment Transactions, as those could significantly affect the revenue pricing structure and require a higher level of strategic insight and control.

System administrators should focus primarily on managing the database backend, which includes setting permissions, maintaining data backups, and overseeing recovery procedures without direct access to the transaction areas that influence business operations. Their primary role is to ensure that the database runs smoothly and securely and that appropriate data protection measures are in place.

Now, examining the backup and recovery strategy at James River Jewelry, it appears that while the company has a system in place, there are several areas for improvement. The use of nightly backups to a second computer is a good initial step, but relying on a single secondary server can be risky. It is advisable to implement a more robust strategy that includes off-site backups for additional redundancy. In addition to the monthly CD backup, cloud storage solutions could be explored, providing more convenient recovery options and potentially reducing the physical risk associated with CD storage at a manager’s house.

Moreover, keeping paper records for an entire year while valuable, should be complemented with a digital logging system that records all transactions and changes within the database. This additional digital record-keeping would facilitate faster audits and data recovery efforts compared to searching through paper records. Additionally, regular testing of the backup and recovery processes should be conducted, ensuring all personnel are familiarized with the recovery protocol in case of an emergency, thus minimizing downtime and data loss.

In summary, by ensuring that Acceptance and Sales Transactions are made atomic, assigning appropriate user rights based on accountability and necessity, and enhancing the existing backup and recovery strategy to be more resilient, James River Jewelry can create a more efficient and reliable database environment that safeguards its operational data integrity and availability.

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