DB2 Query Parallelism: Staging and Implementation

Implementation of Two Semantic Query Optimization Techniques in DB2 Universal Database

Automated Statistics Collection in DB2 UDB

The use of inaccurate or outdated database statistics by the query optimizer in a relational DBMS often results in a poor choice of query execution plans and hence unacceptably long query processing times. Configuration and maintenance of these statistics has traditionally been a time-consuming manual operation, requiring that the database administrator (DBA) continually monitor query performan...

Pathfinder Meets DB2 Relational XQuery Optimization Techniques

We are taking the next big step towards the goal of a purely relational XQuery implementation. The Pathfinder XQuery compiler has been enhanced by a code generator that emits SQL. This code generator targets off-the-shelf relational database systems (e.g., DB2) and turns them into efficient and scalable XQuery processors. Our approach neither depends on modifications of the database kernel, nor...

Integrating the Relational Interval Tree into IBM's DB2 Universal Database Server

User-defined data types such as intervals require specialized access methods to be efficiently searched and queried. As database implementors cannot provide appropriate index structures and query processing methods for each conceivable data type, present-day object-relational database systems offer extensible indexing frameworks that enable developers to extend the set of built-in index structu...

Semantic Query Transformation for Integrating Web Information Sources

The heterogeneousness and dynamics of web information sources are the major challenges to Internet-scale information integration. The information sources are different in contents and query interfaces. In addition, the sources can be highly dynamic in the sense that they can be added, removed, or updated with time. This paper introduces a novel information integration framework that leverages t...