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Insamling, lagring och bearbetning av data för beslutsstöd i stora organisationer
| Content Provider | Semantic Scholar |
|---|---|
| Author | Pettersson, Eva Westerdahl, Johan |
| Copyright Year | 2005 |
| Abstract | In the 1960's the thought of collecting transactional data for decision support arose. To enable decision support in an organisation a data warehouse must be built taking into consideration a variety of techniques for data retrieval, storage and reporting. Our purpose with this dissertation is to describe a data warehouse from a technical perspective, how data is stored, how a data warehouse can be streamlined for fast data retrieval and how to enable scalable data storage. A data warehouse is a subject-oriented, integrated, non volatile, time-variant data store supportive of managerial decisions. We describe an architecture for a data warehouse where the detailed data is normalised according to the relational model. The warehouse data is summarized or aggregated in a fashion designed to accommodate departmental needs and stored in what is called a data mart. Data in a data mart is not normalised but is stored according to the dimensional model which abandons the principles of normalisation in favour of optimized performance. Organisations often need to compare data from multiple tables for which the dimensional model is well suited. The combination of historical and detailed data leads to enormous volume requirements which, in practice, often increases the need for storage exponentially. This demands heavy use of indexing and partitioning of the database. To decrease response time aggregated redundant data is used to a great extent. One of our conclusions is the importance of a pragmatic approach to data warehouse design. The main priority must be to solve the organisation's problems. Following theoretical design principles is of secondary concern. |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | https://www.cs.kau.se/cs/education/courses/davcdiss/Exjobb_2005/C2005-06.pdf |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
