CS614 Final Term Solved Subjective with References by Moaaz

Solved Subjective · From Midterm Papers · Feb 05,2013 · PSMD01 · SPRING 2012

1; what are the two extremes for technical architecture design? 2

Answer: (Page 95) Theoretically there can be two extremes i.e. free space and free performance. If storage is not an issue, then just pre-compute every cube at every unique combination of dimensions at every level as it does not cost anything. This will result in maximum query performance.

2;Different b/w non key or key data access?2

Answer: (Page 231) There are two ways to access data: non-keyed access and keyed access. Non-keyed access uses no index. Each record of the database is accessed sequentially, beginning with the first record, then second, third and so on.

3;“Be a diplomat not a technologist”?2

Answer: (Page 320) The biggest problem you will face during a warehouse implementation will be people, not the technology or the development. You‘re going to have senior management complaining about completion dates and unclear objectives. You‘re going to have development people protesting that everything takes too long and why can‘t they do it the old way? You‘re going to have users with outrageously unrealistic expectations, who are used to systems that require mouse-clicking but not much intellectual investment on their part. And you‘re going to grow exhausted, separating out Needs from Wants at all levels. Commit from the outset to work very hard at communicating the realities, encouraging investment, and cultivating the development of new skills in your team and your users (and even your bosses). Most of all, keep smiling. When all is said and done, you‘ll have a resource in place that will do magic, and your grief will be long past. Eventually, your smile will be effortless and real.

4;Dirty bit?2

Answer: (Page 438)

• It can be boolean type column
• This column will help us in keeping record of rows with errors, during data profiling

5;What are the problem face industry when the growth in usage of master table file increase?3

Answer: (Page 12)

• Data coherency i.e. the need to synchronize data upon update.
• Program maintenance complexity.
• Program development complexity.
• Requirement of additional hardware to support many tapes.

6;Indexing using I/O bottelneck?3

Answer: (Page 221) Throwing more hardware at the problem doesn't really help, either. Expensive and multiprocessing servers can certainly accelerate the CPU-intensive parts of the process, but the bottom line of database access is disk access, so the process is I/O bound and I/O doesn't scale as fast as CPU power. You can get around this by putting the entire database into main memory, but the cost of RAM for a multi-gigabyte database is likely to be higher than the server itself! Therefore we index.

7; what is mean by the classification process? How we measure the accuracy of classifiers? 3

Answer: (Page 259) Classification means that based on the properties of existing data, we have made or groups i.e. we have made classification. Accuracy is the measure of correctness of your model e.g. in classification we have two data sets, training and test sets. A classification model is built based on the data properties and relationships in training data. Once built the model is tested for accuracy in terms of % correct results as the classification of the test data is already known. So we specify the correctness or confidence level of the technique in terms % accuracy.

8;SQL server meta services advantages(3)

Answer: (Page 385) We may maintain meta data information of the databases involved in the packages and we may keep version information of each package. Furthermore package can be stored in a structured file and Microsoft visual basic file.

9;Why pilot strategy is recommended for construction of DWH(5)

Answer: (Page 334) Will adopt a pilot project approach, because:

•  A full-blown DWH requires extensive investment.
•  Show users the value of DSS.
•  Establish blue print for full-blown system.
•  Identify problem areas.
•  Reveal true data demographics.
•  Pilot projects are supposed to work with limited data.

10: Purpose of DTS services(5)

Answer: (Page ) Many organizations need to centralize data to improve corporate decision-making. However, their data may be stored in a variety of formats and in different locations. Data Transformation Services (DTS) address this vital business need by providing a set of tools that let you extract, transform, and consolidate data from disparate sources into single or multiple destinations supported by DTS connectivity. DTS allows us to connect through any data source or destination that is supported by OLE DB. This wide range of connectivity that is provided by DTS allows us to extract data from wide range of legacy systems. Heterogeneous source systems store data with their local formats and conventions. While consolidating data from variety of sources we need to transform names, addresses, dates etc into a standard format. For example consider a student record management system of a university having four campuses. A campus say ‗A‘ follows convention to store city codes ―LHR‖ for Lahore. An other campus say ‗B‘ stores names of cities ―Lahore‖, campus ‗C‘ stores city names in block letters ‗LAHORE‘, and the last campus ‗D‘ store city names as ‗lahore‘. When the data from all the four campuses is combined as it is and query is run ―How many students belong to ‗Lahore‘?‖ We get the answer only from campus B because no other convention for Lahore matches to the one in query. To combine data from heterogeneous sources with the purpose of some useful analysis requires transformation of data. Transformation brings data in some standard format.

11: Explain analytic dta application specification in kimbill 5 marks

Answer: (Data Warehouse Toolkit, Page 363) Following the business requirements definition, we need to review the findings and collected sample reports to identify a starter set of approximately 10 to 15 analytic applications. We want to narrow our initial focus to the most critical capabilities so that we can manage expectations and ensure on-time delivery. Business community input will be critical to this prioritization process. While 15 applications may not sound like much, the number of specific analyses that can be created from a single template merely by changing variables will surprise you. Before we start designing the initial applications, it‘s helpful to establish standards for the applications, such as common pull-down menus and consistent output look and feel. Using the standards, we specify each application template, capturing sufficient inklllformation about the layout, input variables, calculations, and breaks so that both the application developer and business representatives share a common understanding. During the application specification activity, we also must give consideration to the organization of the applications. We need to identify structured navigational paths to access the applications, reflecting the way users think about their business. Leveraging the Web and customizable information portals are the dominant strategies for disseminating application access.