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Formalização do Processo de Tradução de Consultas em Ambientes de Integração de Dados XML
| Content Provider | Semantic Scholar |
|---|---|
| Author | Alves, W. B. |
| Copyright Year | 2008 |
| Abstract | Formalization of a Query Translation Process in XML Data Integration In order to search for the same information in heterogeneous XML data sources, it would be desirable to state a single query against a global conceptual schema and then translate it automatically into an XML query for each specific data source. CXPath (for Conceptual XPath ) has been proposed as a language for querying XML sources at the conceptual level. This language was developed to simplify the translation process of queries at conceptual level to queries at XML level. At the same time, one of the goals of the language design is to facilitate the learning of its syntax. For this reason its syntax is similar to the XPath language used for querying XML documents. In this dissertation, a translation mechanism of queries at conceptual level, written in CXPath, to queries at XML level, written in XPath, is formally defined. The inheritance relationship in the translation mechanism is shown, being discussed the relation between the conceptual model expressivity and the translation mechanism. In some cases, the translation of a CXPath query does not return some of the answers because the data sources may be incomplete. In this work, the conceptual model, which is the basis for the data integration system’s global schema, is improved with inclusion dependencies, and the query answering mechanism is modified to deal with this kind of dependency. More specifically, mechanisms of query rewriting and redundancy elimination are presented to deal with this kind of dependency. This global schema improvement allows infer results, with the data available in the system, that would not be provided with a simple query translation. The approach of data integration used in this dissertation is also presented within the formal framework for data integration proposed by (LENZERINI, 2002). According to the author, that framework is general enough to capture all approaches in the literature, including, in particular, the approach considered in this dissertation. |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | https://lume.ufrgs.br/bitstream/handle/10183/15745/000689467.pdf;jsessionid=A1518C3ED0FA87BA4C6E0D348081DB95?sequence=1 |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
