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Data Warehouses, Decision Support and Data Mining

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TERM PAPER FOR OPERATING SYSTEMS

DATA WAREHOUSES, DECISION SUPPORT AND DATA MINING
Date: 09/11/2011

“I certify that the work contained in this paper is wholly mine. This paper has not been used to meet requirements in another course. It has not been purchased nor written by someone else, nor written for me. Exceptions to the aforementioned constitute plagiarism and an honor and ethics violation and therefore will result in a course grade of F and any other University remedies as appropriate.”

Data Warehouses, Decision Support and Data Mining

Abstract

Data warehousing and on-line analytical processing (OLAP) are key elements of decision support which has primarily become focus on database …show more content…

Data warehouses, in contrast, are targeted for decision support. Historical, summarized and consolidated data is more important than detailed, individual records. Since data warehouses contain consolidated data, perhaps from several operational databases, over potentially long periods of time, they tend to be orders of magnitude larger than operational databases; enterprise data warehouses are projected to be hundreds of gigabytes to terabytes in size. The workloads are query intensive with mostly ad hoc, complex queries that can access millions of records and perform a lot of scans, joins, and aggregates. Query throughput and response times are more important than transaction throughput.

To facilitate complex analyses and visualization, the data in a warehouse is typically modeled multidimensionally. For example, in a sales data warehouse, time of sale, sales district, salesperson, and product might be some of the dimensions of interest. Often, these dimensions are hierarchical; time of sale may be organized as a day-month-quarter-year hierarchy, product as a product-category-industry hierarchy.

Many organizations want to implement an integrated enterprise warehouse that collects information about all subjects (e.g., customers, products, sales, assets, personnel) spanning the whole organization. However, building an enterprise warehouse is a long and complex process, requiring extensive business modeling, and may take many years to succeed. Some

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