1 DATAWAREHOUSING QUESTIONS by Mausami Sawarkar

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1 1 DATAWAREHOUSING QUESTIONS by Mausami Sawarkar 1) What does the term 'Ad-hoc Analysis' mean? Choice 1 Business analysts use a subset of the data for analysis. Choice 2: Business analysts access the Data Warehouse data infrequently. Choice 3: Business analysts access the Data Warehouse data from different locations. Choice 4: Business analysts do not know data requirements prior to beginning work. Choice 5: Business analysts use sampling techniques. 2) What should be the business analyst's involvement in monitoring the performance of a Data Warehouse or Data Mart? Choice 1: Be patient when load monitoring on the Data Warehouse or Data Mart is taking place. Choice 2: Become experts in SQL queries. Choice 3: No involvement in performance monitoring. Choice 4: Contact IT if a query takes too long or does not complete. Choice 5: Complete all required training on the query tools they will be using 3) What factor heavily influences data warehouse size estimates? Choice 1: The design of the warehouse schemas Choice 2: The size of the source system schemas Choice 3: The record size of the source tables Choice 4: The number of expected data warehouse users Choice 5: The number of customers an organization has Data warehouses or data marts allow organizations to define 'alert' conditions -- an alert is raised when something noteworthy has taken place. For implementing a facility of 'alerts', 4) what is the advantage of using a WEB interface over a client/server approach? Choice 1: Access to the 'Alert' report is possible through a highly accessible means already available within the organization. Choice 2: The selection criteria used in determining when an 'alert' needs to be issued is easier to implement using a WEB browser. Choice 3: As long as the appropriate individual can access the 'alert', how it is implemented does not present an advantage. Choice 4:'Alerts' can be directed only to the requestor of the 'alert'. Choice 5: Access to the 'alert' data can be tightly controlled. 5) Which of the following statements correctly describe a Dimension table in Dimensional Modeling? Choice 1: Dimension tables contain fields that describe the facts. Choice 2: Dimension tables do not contain numeric fields. Choice 3: Dimension tables are typically larger than fact tables. Choice 4: Dimension tables do not need system-generated keys. Choice 5: Dimension tables usually have fewer fields than fact tables 6) How are dimensions in a Multi-Dimensional Database related? Choice 1: Hierarchically. Choice 2: Through foreign keys. Choice 3: Through a hierchy and foreign keys. Choice 4: Through a network. Choice 5: Through an inverse list. 7) What is a primary risk of a 'phased' implementation? Choice 1: Previous implementations may need to be reworked. Choice 2: The project may lose momentum. Choice 3: Business Analysts will find problems in the data sooner. Choice 4: Executives will lose focus. Choice 5: The project budget may be exceeded. 2 8 ) How do highly distributed source systems impact the Data Warehouse or Data Mart project? Choice 1: The source data exists in multiple environments.

2 Choice 2: The location of the source systems has minimal impact on the Data Warehouse or Data Mart implementation. Choice 3: The timing and coordination of software development, extraction, and data updates are more complex. Choice 4: Large volumes of data must be moved between locations. Choice 5: Additional network and data communication hardware will be needed. 9) Categories of OLAP Tools: Level 1: Basic query and display of data Level 2: Level 1 + advanced selection and arithmetic operations Level 3: Level 2 + sophisticated data analysis techniques 10) Which of the following is an example of a process performed by a Level 3 OLAP tool (as described above)? Choice 1: Drill down to another level of detail. Choice 2: Display the top 10 items that meet a specific selection criteria. Choice 3: Trend analysis. Choice 4: Calculate a rolling average on a set of data. Choice 5: Display a report based on specific selection criteria. 11) In a Data Mart Only architecture, what will the Data Mart Development Team(s) encounter? Choice 1: There is little or no minimal data redundancy across all of the Data Mart databases. Choice 2: Issues such as inconsistent definitions and dirty data in extracting data from multiple source systems will be addressed several times. Choice 3: Database design will be easier than expected because Data Mart databases support only a single user. Choice 4: There is ease in consolidating the Data Marts to create a Data Warehouse. Choice 5: It is easy to develop the data extraction system due to the use of the warehouse as a single data source. 12) What is the primary responsibility of the 'project sponsor' during a Data Warehouse project? Choice 1: To manage the day-to-day project activity. Choice 2: To review and approve all decisions concerning the project. Choice 3: To approve and monitor the project budget. Choice 4: To ensure cooperation and support from all 'involved' departments. Choice 5: To communicate project status to higher management and the board of directors. 13) What are Metadata? Choice 1: Data used only by the IS organization. Choice 2: Information that describes and defines the organization's data. Choice 3: Definitions of data elements. Choice 4: Any business data occurring in large volumes. Choice 5: Summarized data. 14) How can the managers of a department best understand the cost of their use of the data warehouse? Choice 1: A percentage of the business department's budget should be directed to the maintenance and enhancement of the Data Warehouse. Choice 2: Institute a charge-back system of computer costs for the access to the Data Warehouse. Choice 3: Develop a training program for department management. Choice 4: Provide executive management with computer utilization reports that show what percentage of utilization is due to the Data Warehouse. Choice 5: Business managers should participate in the acquisition process for computer hardware and software. 15) Which of the following is NOT a consequence of the creation of independent Data Marts? 3 Choice 1: Potentially different answers to a single business question if the question is asked of more than one Data Mart.

3 Choice 2: Increase in data redundancy due to duplication of data between the Data Marts. Choice 3: Consistent definitions of the data in the Data Marts. Choice 4:Creation of multiple application systems that have duplicate processing due to the duplication of data between the Data Marts. Choice 5: Increased costs of hardware as the databases in the Data Marts grow. 16) What is meant by artificial intelligence when it is applied to data cleansing and transformation tools? Choice 1: The tool can perform highly complex mathematical and statistical calculations to create derived data elements. Choice 2: The tool can accomplish highly complex code translations when data comes from multiple source systems. Choice 3: The tool can determine through heuristics the changes needed for a set of dirty data and then make the changes. Choice 4: The tool can perform highly complex summarizations across multiple databases. Choice 5: The tool can identify data that appears to be inconsistent between multiple source systems and provide reporting to assist in the clean up of the source system data. 17) Which of the following classes of corporations can gain the most insights from their legacy data? Choice 1: A corporation that wants to determine the attitude of its customers towards the corporation. Choice 2: A corporation that offers new products and services. Choice 3: A new corporation. Choice 4: A corporation that has existed for a long time. Choice 5: A corporation that is constantly introducing new and different products and services. 18) Which of the following is NOT found in an Entity Relationship Model? Choice 1: A definition for each Entity and Data Element. Choice 2: Entity Relationship Diagram Choice 3: Entity and Data Element Names Choice 4: Fact and Dimension Tables Choice 5: Business Rules associated with the entities, entity relationships, and the data elements. 19) What is Data Mining? Choice 1: The capability to drill down into an organization's data once a question has been raised. Choice 2: The setting up of queries to alert management when certain criteria are met. Choice 3: The process of performing trend analysis on the financial data of an organization. Choice 4: The automated process of discovering patterns and relationships in an organization's data. Choice 5: A class of tools that support the manual process of identifying patterns in large databases. 20) What does implementing a Data Warehouse or Data Mart help reduce? Choice 1: The data gathering effort for data analysis. Choice 2: Hardware costs. Choice 3: User requests for custom reports. Choice 4: Costs when management downsizes the organization. Choice 5: All of the above. 21) Profitability Analysis is one of the most common applications of data warehousing. Why is Profitability Analysis in data warehousing more difficult than usually expected? Choice 1: Almost every manager in an organization wants to get profitability reports. Choice 2: Revenue data cannot be tracked accurately. Choice 3: Expense data is often tracked at a higher level of detail than revenue data. Choice 4: Revenue data is difficult to collect and organize. Choice 5: Transaction grain data is required to properly compute profitability figures. 22) Which of the following would NOT be considered a recurring cost of either Data Warehouse User Support or Data Warehouse Administration? Choice 1: Capacity Planning 4 Choice 2: Creation of New Data Marts

4 Choice 3: Security Administration Choice 4: Data Archiving Choice 5: Database Management System Software Selection 23) Why is it important to track all project issues and their resolution? Choice 1: To show management what the project team has accomplished. Choice 2: Issues will be brought back up even after they have been resolved. Choice 3: Provides an audit trail for use in internal or external audits. Choice 4: There is no need to track issues once they are resolved. Choice 5: Tracking is needed for project status report. 24) When a physical database design contains summary data, what must the database designer always ensure? Choice 1: Non-numeric (non-summary) data elements should not be placed in a summary table. Choice 2: The detail data used to create the summary data is kept in case the Data Warehouse database needs to be reloaded. Choice 3: The level of detail lost by summarization will not affect the business analysts' use of the data. Choice 4: Each table with summary data has a 'from' and 'to' date. Choice 5: The appropriate business rule(s) describing how the data will be summarized is in place. 25) Which of the following is a business benefit of a Data Warehouse? Choice 1: Customers are happier. Choice 2: Reduction in Government interference. Choice 3: Decision makers will be able to make more decisions each day. Choice 4: Ability to identify historical trends. Choice 5; Improves morale of the business analysts. 26) How does Ad-hoc Access differ from Managed Query Access? Choice 1: Ad-hoc access provides users more flexibility when retrieving data. Choice 2: Ad-hoc query access requirements are easier to anticipate. Choice 3: Managed query access is more frequently implemented. Choice 4: Managed query access give users more ways of getting the data they need. Choice 5:Managed query response times are easier to optimize. 27) What is a 'snowflake' schema? Choice 1: The dimension tables are 'normalized'. Choice 2: The dimension tables can refer to more than one fact table. Choice 3: All recurring groups of attributes are completely removed from dimension tables. Choice 4: A schema that can be implemented only with an MDDB Database Management System. Choice 5: Any database implemented with a network Database Management System. 28) Which of the following describes a successful decision support environment? Choice 1: Depends heavily on sets of 'canned' queries to provide good performance and reduced costs Choice 2: Has data warehouse and data mart databases that are of terabyte size Choice 3: Costly Choice 4: Totally independent of the operational systems Choice 5: Iterative and evolutionary 29) What is an Operational Data Store? Choice 1: A set of databases that serve as a 'staging' area to facilitate consolidating data from several, distributed-source systems. Choice 2: A set of databases that support OLAP. Choice 3: A set of databases that support reporting from an application system. 5 Choice 4: A set of databases that provide integrated operations data to serve the organization's day-to-day activities. Choice 5: A set of databases to provide operational data for a single department. 30) When is it appropriate to 'denormalize' a relational database design for a Data Warehouse database? Choice 1: When disk space is low. Choice 2: When memory is low. Choice 3: When the analysis requirements are understood. Choice 4: Any time. Choice 5: When the database design is no longer expected to change.

5 31) Where in the warehouse architecture is it appropriate to calculate 'derived' data elements for storage? Choice 1: As part of the business analysts' queries. Choice 2: In an application system developed solely to address 'derived' data elements. Choice 3: When the data are extracted from the source systems. Choice 4: After the business analysts have extracted their data from the Data Warehouse. Choice 5: Just prior to loading the data into the Data Warehouse databases 32) In an architecture where 'atomic' data are maintained in the Data Warehouse and used to create the Data Marts, what is the best implementation for the Data Warehouse databases? Choice 1: Multi-Dimensional Database Management System Choice 2: Hierarchical Database Management System Choice 3: Relational Database Management System Choice 4: Object Database Management System Choice 5: Any Database Management System is acceptable. 33) Why would an organization decide to implement a Data Warehouse on a mainframe computer with its OLTP applications? Choice 1: For cost considerations only. Choice 2: For improved response time on queries to the Data Warehouse. Choice 3: The size of the Data Warehouse has outgrown the small computer's capability of handling it. Choice 4: To avoid large network requirements as a result of having to move large amounts of data between platforms and database management systems. Choice 5: The number of Data Warehouse users has increased to a point where the smaller platforms cannot handle them. 34) What are the characteristics of a good candidate for a Web application? Choice 1: One that provides data in multiple formats to a small group of business analysts and management. Choice 2: Any application intended to be used by executive management. Choice 3: One that provides data in multiple formats and that requires a low level of processing to a large number of users. Choice 4: Any application providing access to a Data Warehouse, Data Mart, or Operational Data Store. Choice 5: One that requires intensive processing and provides data in a few formats to a large number of users. 35) What does the statement "A Data Warehouse database is non-volatile" mean? Choice 1: Data Warehouse databases contain only historical transaction data. Choice 2: Business requirements for a Data Warehouse are stable. Choice 3: Data Warehouse database structures change very infrequently. Choice 4: Data within the databases do not change from second to second. Choice 5: Data Warehouse databases support the creation of a set of reports. 36) What is typically discovered when historical data are first extracted from legacy systems for initial loading into the Data Warehouse? Choice 1: Flaws in the warehouse database design. Choice 2: Flaws in the extraction program code. Choice 3: The need for additional data sources. Choice 4: Extraction run times are shorter than expected. Choice 5: Undocumented changes in the content, usage, and structure of the historical data. 6 37) What is typically discovered when historical data are first extracted from legacy systems for initial loading into the Data Warehouse? Choice 1: Flaws in the warehouse database design. Choice 2: Flaws in the extraction program code. Choice 3:The need for additional data sources. Choice 4: Extraction run times are shorter than expected. Choice 5: Undocumented changes in the content, usage, and structure of the historical data.

6 38) What is an operational system? Choice 1: An application system that tracks and manages the financial assets of the organization. Choice 2: An application system that supports the planning and forecasting within the organization. Choice 3: An application system that supports the creation of product(s) that the organization markets. Choice 4: An application system that supports the organization's day-to-day activities. Choice 5:An application system that supports the organization's decision-making. 39) If a Data Warehouse is to be implemented in a distributed architecture, what could be the most difficult part of the implementation? Choice 1: Finding and selecting query and reporting tools that can span multiple databases. Choice 2: Finding and selecting the tools to monitor database performance. Choice 3: Convincing the business analysts that this approach will work. Choice 4: Developing an estimated Data Warehouse workload. Choice 5: Designing the Data Warehouse databases. 40) What is a primary risk of a 'phased' implementation? Choice 1: Previous implementations may need to be reworked. Choice 2: The project may lose momentum. Choice 3: Business Analysts will find problems in the data sooner. Choice 4: Executives will lose focus. Choice 5: The project budget may be exceeded. 41) Data warehouses or data marts allow organizations to define 'alert' conditions -- an alert is raised when something noteworthy has taken place. For implementing a facility of 'alerts', what is the advantage of using a WEB interface over a client/server approach? Choice 1: Access to the 'Alert' report is possible through a highly accessible means already available within the organization. Choice 2:The selection criteria used in determining when an 'alert' needs to be issued is easier to implement using a WEB browser. Choice 3: As long as the appropriate individual can access the 'alert', how it is implemented does not present an advantage.: Choice 4: 'Alerts' can be directed only to the requestor of the 'alert'. Choice 5: Access to the 'alert' data can be tightly controlled 42) What should be the business analyst's involvement in monitoring the performance of a Data Warehouse or Data Mart? Choice 1: Be patient when load monitoring on the Data Warehouse or Data Mart is taking place. Choice 2: Become experts in SQL queries. Choice 3: No involvement in performance monitoring. Choice 4: Contact IT if a query takes too long or does not complete. Choice 5: Complete all required training on the query tools they will be using. 43) What is multidimensional data modeling? Where are the advantages? Ans. ==================