* Distributed Query Processing [#ucf7b125]
We aim to develop tools for integrating heterogeneous data, including relational, XML and Web data sources. As part of this project, the OGSA-DQP service-based distributed query processor, which was developed as part of the OGSA-DAI UK e-Science project, has been extended to work with OGSA-WebDB and XML data sources.
Here, a source release of the extensions is available. The extensions are compatible with OGSA-DAI 3.0 Axis. You will need a working installation of OGSA-DQP 3.2.1 onto which the extensions can be applied.
A source release of the extensions is available [[here>Page:OGSA-DQP3.2.1/Download/Version 1.0]]. The extensions are compatible with OGSA-DAI 3.0 Axis. You will need a working installation of OGSA-DQP 3.2.1 onto which the extensions can be applied.
** Overview [#p63cb6ab]
The following two tools for providing data integration for e-Science applications are extended:
OGSA-DAI (OGSA Data Access & Integration):
-Service-based Grid computing middleware.
-Built on OGSA 窶 the Open Grid Services Architecture
-Wraps various relational and XML databases.
-A way of securely exposing data via Web services.
OGSA-DQP (OGSA distributed query processor):
-Provides integration in the form of a distributed query processor.
-Uses OGSA-DAI wrappers.
-Also integrates analysis by invoking Web services.
-Declarative interface based on SQL.
-Other benefits include parallelism during query execution.
The extensions to OGSA-DQP:
- Provide support for querying Web-accessible databases.
- Provide support for XML data though extensions to the query language and evaluation infrastructure
** Architecture [#c64f642a]
The extended system is able to integrate OGSA-WebDB-wrapped databases, OGSA-DAI-wrapped relational/XML databases and analysis (Web) services.
CENTER:#ref(dqpx1.jpg);
** Future Plans [#lb7e8cfc]
- Modify the query compiler to support a move expressive query language.
- Address performance issues by (i) investigating alternative query optimisation strategies, (ii) improving the efficiency of query evaluation infrastructure, in particular where data is fetched from OGSA-DAI and OGSA-WebDB.
** Links [#v191f4ac]
- [[OGSA-DAI>http://www.ogsadai.org.uk]]
- [[OGSA-DQP>http://www.ogsadai.org.uk/dqp]]
- [[OGSA-WebDB>http://dbgrid.org/OGSA-WebDB]]
** Acknowledgements [#l8d6c653]
This work was made possible by the support of the [[Japan Society for the Promotion of Science>http://www.jsps.go.jp]] (JSPS).
