What is a transaction log, and what is its function?
> While working as a database analyst for a national sales organization, you are asked to be part of its data warehouse project team. Prepare a high-level summary of the main requirements for evaluating DBMS products for data warehousing.
> Give three examples of likely problems when operational data are integrated into the data warehouse.
> What is a data warehouse, and what are its main characteristics? How does it differ from a data mart?
> What are the most relevant differences between operational and decision support data?
> Explain how the main components of the BI architecture interact to form a system. Describe the evolution of BI information dissemination formats.
> What are decision support systems, and what role do they play in the business environment?
> Discuss the most common performance improvement techniques used in star schemas.
> In the star schema context, what are attribute hierarchies and aggregation levels and what is their purpose?
> Describe the BI framework. Illustrate the evolution of BI.
> Explain multidimensional cubes, and describe how the slice and dice technique fits into this model.
> Create a query to find the customer balance characteristics for all customers, including the total of the outstanding balances. The results of this query are shown in Figure P7.39. FIGURE P7.39 Customer Balance Summary for All Customers Total Balan
> Explain the use of facts, dimensions, and attributes in the star schema.
> Explain ROLAP, and list the reasons you would recommend its use in the relational database environment.
> What is OLAP, and what are its main characteristics?
> Briefly discuss OLAP architectural styles with and without data marts.
> While working as a database analyst for a national sales organization, you are asked to be part of its data warehouse project team. The data warehouse project is in the design phase. Explain to your fellow designers how you would use a star schema in the
> While working as a database analyst for a national sales organization, you are asked to be part of its data warehouse project team. The project group is ready to make a final decision between ROLAP and MOLAP. What should be the basis for this decision? W
> While working as a database analyst for a national sales organization, you are asked to be part of its data warehouse project team. One of your vendors recommends using an MDBMS. How would you explain this recommendation to your project leader?
> While working as a database analyst for a national sales organization, you are asked to be part of its data warehouse project team. The data warehousing project group has invited you to provide an OLAP overview. The group’s members are particularly conce
> While working as a database analyst for a national sales organization, you are asked to be part of its data warehouse project team. Suppose you are selling the data warehouse idea to your users. How would you define multidimensional data analysis for the
> What is business intelligence? Give some recent examples of BI usage, using the Internet for assistance. What BI benefits have companies found?
> Using the results of the query created in Problem 37, provide a summary of customer balance characteristics as shown in Figure P7.38. FIGURE P7.38 Balance Summary for Customers Who Made Purchases Minimum Balance Maximum Balance Average Balance 345.
> How does a BASE system differ from a traditional distributed database system?
> What trade-offs are involved in building highly distributed data environments?
> What are the two basic styles of data replication?
> What issues should be considered when resolving data requests in a distributed environment?
> To which transparency feature are the query optimization functions related?
> What is the objective of the query optimization functions?
> Describe the different types of database requests and transactions.
> If indexes are so important, why not index every column in every table? (Include a brief discussion of the role played by data sparsity.)
> In simple terms, the DBMS processes queries in three phases. What are those phases, and what is accomplished in each phase?
> How is the processing of SQL DDL statements (such as CREATE TABLE) different from the processing required by DML statements?
> List the balance characteristics of the customers who have made purchases during the current invoice cycle—that is, for the customers who appear in the INVOICE table. The results of this query are shown in Figure P7.37. FIGURE P7.37 Ba
> What database statistics measurements are typical of tables, indexes, and resources?
> How are database statistics obtained?
> What are database statistics, and why are they important?
> What is the focus of most performance tuning activities, and why does that focus exist?
> What is database performance tuning?
> What does RAID stand for, and what are some commonly used RAID levels?
> What recommendations would you make for managing the data files in a DBMS with many tables and indexes?
> Most query optimization techniques are designed to make the optimizer’s work easier. What factors should you keep in mind if you intend to write conditional expressions in SQL code?
> What are some general guidelines for creating and using indexes?
> What are optimizer hints and how are they used?
> Using the query results in Problem 35 as your basis, write a query to generate the total number of invoices, the invoice total for all of the invoices, the smallest of the customer purchase amounts, the largest of the customer purchase amounts, and the a
> What is the difference between a rule-based optimizer and a cost-based optimizer?
> What is SQL performance tuning?
> What are the different levels of lock granuality?
> What is a lock, and how, in general, does it work?
> What is a scheduler, what does it do, and why is its activity important to concurrency control?
> What does serializability of transactions mean?
> List and discuss the five transaction properties.
> The DBMS does not guarantee that the semantic meaning of the transaction truly represents the real-world event. What are the possible consequences of that limitation? Give an example.
> What is a consistent database state, and how is it achieved?
> Write a query to produce the number of invoices and the total purchase amounts by customer, using the output shown in Figure P7.35 as your guide. (Compare this summary to the results shown in Problem 34.) FIGURE P7.35 Number of Invoices and Total Purcha
> What are the four ANSI transaction isolation levels? What type of reads does each level allow?
> What are the three types of database critical events that can trigger the database recovery process? Give some examples for each one.
> Why might it take a long time to complete transactions when an optimistic approach to concurrency control is used?
> What are some disadvantages of time-stamping methods for concurrency control?
> What is a deadlock, and how can it be avoided? Discuss several strategies for dealing with deadlocks.
> What is an exclusive lock, and under what circumstances is it granted?
> What is concurrency control, and what is its objective?
> Why might a page-level lock be preferred over a field-level lock?
> Explain the following statement: a transaction is a logical unit of work.
> What is the data dictionary's function in database design?
> Use a query to show the invoices and invoice totals as shown in Figure P7.34. (Hint: Group by the CUS_CODE.) FIGURE P7.34 Invoice Totals by Customer CUS CODE INV NUMBER Invoice Total 10011 1002 9.98 10011 1004 34.87 10011 1008 399.15 10012 1003 15
> What are business rules? Why are they important to a database designer?
> Discuss the distinction between top-down and bottom-up approaches to database design.
> What is the minimal data rule in conceptual design? Why is it important?
> Discuss the distinction between centralized and decentralized conceptual database design.
> What does the acronym DBLC mean, and what does a DBLC portray?
> What does the acronym SDLC mean, and what does an SDLC portray?
> How do systems analysis and systems development fit into a discussion about information systems?
> What three levels of backup may be used in database recovery management? Briefly describe what each of those three backup levels does.
> List and briefly explain the three steps performed during the physical design stage.
> List and briefly explain the four steps performed during the logical design stage.
> Create a query to produce the total purchase per invoice, generating the results shown in Figure P7.33. The Invoice Total is the sum of the product purchases in the LINE that corresponds to the INVOICE. FIGURE P7.33 Invoice Totals INV NUMBER Invoic
> What factors are important in a DBMS software selection?
> List and briefly explain the activities involved in the verification of an ER model.
> What steps are required in the development of an ER diagram? (Hint: See Table 9.3.)
> What is an information system? What is its purpose?
> The relational set operators UNION, INTERSECT, and MINUS work properly only if the relations are union-compatible. What does union-compatible mean, and how would you check for this condition?
> What does it mean to say that SQL operators are set-oriented?
> Explain the difference between a regular subquery and a correlated subquery.
> What is a correlated subquery? Give an example.
> What are the three types of results a subquery can return?
> What is a subquery, and what are its basic characteristics?
> Use a query to compute the average purchase amount per product made by each customer. (Hint: Use the results of Problem 31 as the basis for this query.) Your output values must match those shown in Figure P7.32. Note that the Average Purchase Amount is e
> Using tables named T1 and T2, write a query example for each of the three join types you described in Question 2. Assume that T1 and T2 share a common column named C1. Data from Question 2: LEFT [OUTER] JOIN RIGHT [OUTER] JOIN FULL [OUTER] JOIN.
> What three join types are included in the OUTER JOIN classification?
> Given the employee information in Question 11, what is the query output for the UNION ALL query? (List the query output.) Details from Question 11: Suppose that you have two tables, EMPLOYEE and EMPLOYEE_1. The EMPLOYEE table contains the records for th
> Suppose that you have two tables, EMPLOYEE and EMPLOYEE_1. The EMPLOYEE table contains the records for three employees: Alice Cordoza, John Cretchakov, and Anne McDonald. The EMPLOYEE_1 table contains the records for employees John Cretchakov and Mary Ch
> What is the difference between UNION and UNION ALL? Write the syntax for each.
> What is a CROSS JOIN? Give an example of its syntax.
> What is dynamic SQL, and how does it differ from static SQL?
> What is embedded SQL, and how is it used?
> What is a stored procedure, and why is it particularly useful? Give an example.
> What is a trigger, and what is its purpose? Give an example.
> Modify the query in Problem 30 to include the number of individual product purchases made by each customer. (In other words, if the customer’s invoice is based on three products, one per LINE_NUMBER, you would count three product purcha
> What is a sequence? Write its syntax.
> What string function should you use to list the first three characters of a company’s EMP_LNAME values? Give an example, using a table named EMPLOYEE.
