In this dissertation, we propose new design guidelines to reduce the amount of redundancy that databases carry. We use techniques from information theory to define a measure that evaluates a database design based on the worst possible redundancy carried in the instances. We then continue by revisiting the design problem of relational data with functional dependencies, and measure the lowest price, in terms of redundancy, that has to be paid to guarantee a dependency-preserving normalization for all schemas. We provide a formal justification for the Third Normal Form (3NF) by showing that we can achieve this lowest price by doing a good 3NF normalization.
We then study the design problem for XML documents that are views of relational data. We show that we can design a redundancy-free XML representation for some relational schemas while preserving all data dependencies. We present an algorithm for converting a relational schema to such an XML design.
We finally study the design problem for XML documents that are stored in relational databases. We look for XML design criteria that ensure a relational storage with low redundancy. First, we characterize XML designs that have a redundancy-free relational storage. Then we propose a restrictive condition for XML functional dependencies that guarantees a low redundancy for data values in the relational storage.
| Identifer | oai:union.ndltd.org:TORONTO/oai:tspace.library.utoronto.ca:1807/11221 |
| Date | 31 July 2008 |
| Creators | Kolahi, Solmaz |
| Contributors | Libkin, Leonid |
| Source Sets | University of Toronto |
| Language | en_ca |
| Detected Language | English |
| Type | Thesis |
| Format | 639178 bytes, application/pdf |
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