Query Translation in Heterogeneous Database Environments
Edgar Jasper · 2002
Aims and Background 1 1.1 General Background 1 1.2 Specific Background 1 1.3 Aims of the Project 2 2. Specification 3 2.1 Input to the Query Translation Tool 3 2.2 General Issues 6 2.3 Output from the Query Translat ion Tool 7 3. Design 8 3.1 Design of lexer and parser 8 3.2 The Structure of the Abstract Syntax Tree 8 3.3 Query Translation 10 3.4 Query Simplification 11 4. Implementation 14 4.1 Research and Reading 14 4.2 Parsing the Input 14 4.3 Translating the Query 15 4.4 Simplifying the Query 16 4.5 Testing the Software 17 5. Conclusions 20 5.1 Problems with the Project 20 5.2 Possible Improvements to the Software 20 5.3 Final Conclusions 21 References 22 Appendices 23 Appendix A -- Java Files 23 Node.java 23 Substituter.java 25 Simplifier.java 29 Elements.java 32 TestDriver.java 33 Appendix B -- CUP and JLex Files 36 EdCup1.cup 36 EdLex1 40 Appendix C -- Text Files 42 Appendix D -- Running Instructions 44 ii ABSTRACT One of the things that must be achieved to implement a he...