Are you unsure which XML indexes you should create for your SQL/XML, XQuery workload? IBM XML Index Advisor for DB2 for Linux, UNIX, and Windows recommends the best set of indexes for your workload within your disk constraint. For DB2 pureXML, the tool outputs the DDL statements to create the recommended indexes and checks for duplicate XML indexes in your database.

How does it work?

IBM XML Index Advisor for DB2 for Linux, UNIX, and Windows is a Java application that works on DB2 V9.5 fp3 (or above) for Unix and Linux platforms, and on DB2 9.7 FP1 (or above) for Windows. IBM XML Index Advisor for DB2 for Linux, UNIX, and Windows recommends XML indexes for a given workload. It takes a set of queries (XQuery, SQL/XML), database characteristics and disk space constraints as an input.

Using these characteristics, IBM XML Index Advisor for DB2 for Linux, UNIX, and Windows uses IBM DB2 Query Optimizer to determine a basic set of XML index candidates. This set of candidates is used to calculate the possible benefit of each index, by using the provided statistics. A search algorithm determines the optimal XML indexes which improve the query performance within the specified disk constraint. IBM XML Index Advisor for DB2 for Linux, UNIX, and Windows outputs the DDL which can be used to create the recommended indexes.

To avoid existence of syntactically different yet semantically identical XML indexes in your database, IBM XML Index Advisor for DB2 for Linux, UNIX, and Windows checks your database for duplicate indexes and presents them to you.

Daniel Zilio is a senior software developer in IBM Toronto. He attained his Ph.D. from the University of Toronto in the area of physical database design selection algorithms.

Calisto Zuzarte is a Senior technical Staff Member (STSM) and is a DB2 architect and manager of the DB2 Compiler team. He specializes in Query Optimization.

Iman Elghandour is a Ph.D. student at the University of Waterloo. She is a member of the Database group and she was funded by a Fellowship from the Center for Advanced Studies at IBM Toronto.

Wolfgang Krause holds a Bachelor of Science degree in computer science from University of Jena. He is currently writing his Master thesis at the IBM Toronto lab in the area of pureXML.

Piotr Mierzejewski is a prototype developer working for the Center for Advanced Studies at IBM Toronto.

Ashraf Aboulnagai is an associate professor at the University of Waterloo. His research interests are in the area of database systems.

Fei Chiang is a Ph.D. candidate in the Department of Computer Science at the University of Toronto. Her research interests are in the efficient management of uncertain and inconsistent data and data quality.

Dr. Andrey Balmin is a research staff member at IBM's Almaden Research Center, where his research interests include search, querying, and management of semistructured data. He was a part of the team that extended DB2 LUW to provide native XML support, and was responsible for XML index eligibility and XML cardinality and cost estimation modules. He received a Ph.D. degree from the University of California at San Diego.

Kevin Beyer is a Research Staff Member at the IBM Almaden Research Center. Dr. Beyer led the design and implementation of the XML indexing support inside DB2 pureXML.