Rainbow - Bridging XML and Relational Databases: Design, Implementation, and Evaluation MQP Project Members: MQP Advisor: Tien Vu, Prof. Elke A. Rundensteiner, Ph. D Mirek Cymer, Sponsor: John Lee Verizon Laboratories Incorporated 04 -19 -2001 1
HTML vs. XML 04 -19 -2001 2
XML Data Management by RDBMS n Microsoft, IBM, Informix, Oracle, . . . n Advantages: Matured database tools available. u Efficient query and analysis tools. u Easy integration with existing business databases. u n Issues: Map between XML and Relational Model. u Update Propagation. u Query Translation and Optimization. u 04 -19 -2001 3
Traditional System Architecture XML Query User XML Legend XML Query Engine XML Data RDBMS Sub system XML Manager XML 04 -19 -2001 4
Motivation for Flexible Mapping n Query Performance varies with respect to how data is mapped. Car iid pid 1 0 … SELECT * FROM model; … Make iid pid 2 1 Ford … … SELECT model FROM car WHERE make = ‘Ford’; Value … car iid pid Make Model 1 Model iid pid 1 Mustang … … … Value 3 Ford Mustang 2001 … … … Year iid pid Value 3 04 -19 -2001 0 Year 1 2001 … … … 5
Rainbow Architecture XML Query User XML Legend XML Query Engine Restructuring Subsystem DTD Manager DTD RDBMS XML Manager XML Data Sub system XML n Flexible mapping = fixed Mapping + restructuring 04 -19 -2001 6
Goals of our MPQ n Target: u n Implement and evaluate restructuring subsystem within the large-scale Rainbow system. Methodology: u u u Learn about the database technologies and web tools. Translate research ideas to software system design. Practice software engineering techniques. Design an experimental test plan and test bed. Conduct performance study and analysis. 04 -19 -2001 7
Rainbow Restructuring Subsystem XML Query User XML Legend XML Query Engine Sub system Data Restructuring Subsystem Process DTD Manager DTD 04 -19 -2001 XML Manager XML 8
Rainbow Restructuring Subsystem XML Query User XML Legend XML Query Engine Restructuring Sub system Mapping Data Restructure Operator Library Restructurer Process DTD Manager DTD 04 -19 -2001 XML Manager XML 9
Restructuring Library Optimization t Pushup/Pushdown Attribute t Pushup/Pushdown Nesting u Organization t Rename Item/Attribute u Completeness t Switch. Nesting t Split/Merge Nesting t Reference/Dereference u 04 -19 -2001 10
Pushup Attribute Operator A B A Push-up B a b CREATE VIEW new. A (<all-columns>, a) AS ( SELECT A. <all_columns>, B. b A. FROM old. A, old. B WHERE B. pid = A. iid CREATE VIEW new. B (<all-columns-but-b>) AS ( SELECT B. <all-columns-but-b> B. FROM old. B 04 -19 -2001 11
Instantiated Restructuring Operators n Mapping = Operators + Parameters. push. Up. Attribute(‘Model’, ‘Value’, ‘Car’, ‘Model’); Car Value Parent Model Parent Mustang Model Value Parent Mustang 04 -19 -2001 12
Rainbow Implementation n n Development Tools u Java: Visual Café 2, Javadocs, JAVA 2 u Oracle 8 i, XML 4 J, JDBC 1. 2, SQL Queries Code Facts u 44 total system classes u 17 classes created by Rainbow u 19 classes extended u 8 classes reused 04 -19 -2001 13
Screen Shot of Rainbow 04 -19 -2001 14
Setup for Rainbow Evaluation n Experimental u u n Database Server: t Oracle 8 i on a PII 300 MHz, 256 MB, Microsoft NT Server Client: t Pentium 233 MHz, 128 MB, Microsoft NT Workstation Data u u Designed a DTD Generated XML using IBM’s XML-Generator 04 -19 -2001 DTD CONTENT: <!ELEMENT one (two+)> <!ELEMENT two (three)> <!ELEMENT three (four)> <!ELEMENT four (five)> <!ELEMENT five (six)> <!ELEMENT six (seven)> <!ELEMENT seven EMPTY> <!ATTLIST seven attribute #REQUIRED> 15
Query Performance Evaluation 04 -19 -2001 16
Overhead Cost 04 -19 -2001 17
MQP Accomplishments n Technical accomplishments Implemented functional prototype system u Confirmed feasibility of Rainbow architecture u Designed automated test bed u Conducted preliminary experimental studies u n Knowledge acquired OO, Java, JDBC, SQL, RDBMS, XML, DTD u Teamwork & S/W Engineering & Software Reuse u Logistics of setting up and running experiments u 04 -19 -2001 18
Potential Future Work XML query translation to SQL u Experiment with test plans and test beds to realize the full potential of the restructuring component. u 04 -19 -2001 19
Special thanks to: Prof. Elke A. Rundensteiner Ph. D. Xin Zhang Visit Rainbow at http: //davis. wpi. edu/dsrg/TJM/ Project Members: Tien Vu, Mirek Cymer, John Lee 04 -19 -2001 20
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