Inferring and Applying Functional Dependencies in Schematic Discrepant Transformations
| dc.contributor.author | Tok Wang LING | en_US |
| dc.contributor.author | Qi HE | en_US |
| dc.date.accessioned | 2004-10-21T14:28:52Z | en_US |
| dc.date.accessioned | 2017-01-23T07:00:03Z | |
| dc.date.available | 2004-10-21T14:28:52Z | en_US |
| dc.date.available | 2017-01-23T07:00:03Z | |
| dc.date.issued | 2003-06-01T00:00:00Z | en_US |
| dc.description.abstract | In relational model, schematic discrepancy occurs when the same information is modeled differently as attribute values, attribute names, relation names or database names in different schemas. Originally raised in schema integration, people have identified many applications of it recently. This paper focuses on the inference and use of functional dependency (FD) constraints in the transformations among schematic discrepant schemas. We first study restructur-ing operators which are used to implement schematic discrepant transformations. Specifically, we study the reconstructibility and commutativity of restructuring operators, which can be used to simplify a transformation. Then to infer FDs in transformed relations, we propose restricted FDs to represent integrity con-straints in original relations. We also study the properties on how restricted FDs change when applying each kind of restructuring operators. Then we give an al-gorithm to infer FDs in schematic discrepant transformations. Our algorithm can compute all FDs in transformed relations which can be inferred from restricted FDs in original relations. At last, we identify the use of FDs in 3 scenarios: (1) use FDs to judge the correctness of SchemaSQL views; (2) use FDs to normalize a transformed relation; (3) use FD constraints to verify the integrity of data from different sources. | en_US |
| dc.format.extent | 536930 bytes | en_US |
| dc.format.mimetype | application/pdf | en_US |
| dc.identifier.uri | https://dl.comp.nus.edu.sg/xmlui/handle/1900.100/1431 | en_US |
| dc.language.iso | en | en_US |
| dc.relation.ispartofseries | TRD6/03 | en_US |
| dc.title | Inferring and Applying Functional Dependencies in Schematic Discrepant Transformations | en_US |
| dc.type | Technical Report | en_US |