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 3 1 Mustang … … … Year Ford Mustang 2001 … … Year iid pid Value 3 04 -19 -2001 0 … Value Model 1 Model Make 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
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 7
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 8
Restructuring Operator Library n n Library contains following operators: u Pushup/Pushdown Attribute u Pushup/Pushdown Nesting u Rename Item/Rename Attribute u Switch. Nesting u Split/Merge Nesting u Reference/Dereference Operator is composed of u DTD Modifications u Data Changes 04 -19 -2001 9
Pushup Attribute Operator DTD Modifications: In A Data Changes: Out A CREATE VIEW out. $A AS SELECT p. <all_columns>, c. $x p. B B x x FROM in. $A p, in. $B c WHERE c. pid = p. iid CREATE VIEW out. $B AS Pushup 04 -19 -2001 SELECT <all-columns-but-x> FROM in. $B 10
Instantiated Pushup Operator DTD Modifications: In Out Car Model Data Changes: Value CREATE VIEW out. Car AS SELECT p. iid, p. pid, c. value FROM in. Car p, in. Model c WHERE c. pid = p. iid CREATE VIEW out. Model AS SELECT iid, pid FROM in. Model Value Pushup 04 -19 -2001 push. Up. Attribute(‘Model’, ‘Value’, ‘Car’, ‘Model’); 11
Mapping is a Sequence of Instantiated Operators For Example: n n 1. push. Up. Attribute(‘Model’, ‘Value’, ‘Car’, ‘Model’); 2. rename. Attribute(‘Car’, ‘Value’, ‘Model’); car Car iid pid 1 car iid pid 1 … … Model 1 0 Mustang … 0 Value … … iid pid 2 Model 1 0 Mustang … … … Model iid pid Value iid pid 3 Mustang 3 1 … … … 1 … … 04 -19 -2001 12
Rainbow Implementation n Development Tools u u n Java: Visual Café 4, Javadoc, JAVA 2 Oracle 8 i, XML 4 J, JDBC 1. 2, SQL Statistics of Class Implementation u 44 total u 17 created u 19 extended u 8 reused 04 -19 -2001 13
Screen Shot of Rainbow 04 -19 -2001 14
Screen Shot of Rainbow 04 -19 -2001 15
Screen Shot of Rainbow 04 -19 -2001 16
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> 17
Query Performance Evaluation 04 -19 -2001 18
Overhead Cost 04 -19 -2001 19
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 Logistics of setting up experiments u Teamwork & S/W Engineering & Software Reuse u 04 -19 -2001 20
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 21
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 22
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