Semantic query optimization for XML databases based on equivalent transformation framework | |
| Author | Pongtawat Chippimolchai |
| Call Number | AIT Diss. no.CS-06-01 |
| Subject(s) | Query languages (Computer science) XML (Document markup language) |
| Note | A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Engineering, School of Engineering and Technology |
| Publisher | Asian Institute of Technology |
| Series Statement | Dissertation ; no. CS-06-01 |
| Abstract | Query optimization, which aims to reduce query evaluation time, is crucial to the success of XML database systems because of the complex structure of XML data and XML queries. Existing optimization tech¬niques neither take the advantage of the rich semantic knowledge available in XML databases nor utilize it in a systematic and efficient manner, resulting in significant reduction of optimization opportunities. Aiming to address these deficiencies, an XML Semantic Query Optimization framework, which employs XML Declarative Description (XDD) theory to model XML databases, XML semantic queries as well as semantic knowledge, is proposed and developed. It uses Equivalent Transformation framework as a basis for query optimization at the semantic (logical) level. The framework fully utilizes, in a systematic way, available semantic knowledge in a database and its schema, and allows flexible but precise control of query optimization processes. Semantic knowledge, formulated as XML Integrity Constraints, is used to prepare XML Equivalent Transformation (XET) rules, which represent semantic-preserving transformations of XML seman¬tic queries. Given queries are transformed by XET rules into syntactically different but semantically equivalent and more efficient forms. Therefore, the result produced by the framework is always correct, which can be formally proved. In addition, the generalized version of the framework is applicable to other type of databases providing that they can be modeled under Declarative Description theory |
| Year | 2006 |
| Corresponding Series Added Entry | Asian Institute of Technology. Dissertation ; no. CS-06-01 |
| Type | Dissertation |
| School | School of Engineering and Technology (SET) |
| Department | Department of Information and Communications Technologies (DICT) |
| Academic Program/FoS | Computer Science (CS) |
| Chairperson(s) | Vilas Wuwongse; |
| Examination Committee(s) | Peter Haddawy;Erik L. J. Bohez; |
| Scholarship Donor(s) | Royal Thai Government; |
| Degree | Thesis (Ph.D.) - Asian Institute of Technology, 2006 |