ZING : Implementing SRW

Hello,
 
I see that there is now a growing list of SRW/SRU Implementers and I thought that I might add a few words about our own project. It may sound familiar because I talked to some of you about it at the ZIG meeting in October last year :-)

The ARTISTE project (http://www.artisteweb.org/) is investigating the use of integrated content and metadata-based image retrieval across disparate databases in several major galleries across Europe. As part of the project we are implementing a distributed query layer as a web service following the SRW specification. 

The ARTISTE architecture follows a standard n-tier approach in which the server has been implemented within a J2EE/EJB framework using the JBoss Enterprise Application Server. The ARTISTE system enables queries to be executed across multiple, distributed collections without requiring each collection to conform to a standard schema. This is achieved by using RDF to define the syntax and semantics of all the metadata terms used as well as existing standard metadata sets such as Dublin Core. A mapping is then made which relates these terms to individual database table and column values. Queries are composed using RDF, and subsequently translated to SQL at each site.

In implementing the SRW we have been thinking about some of the issues listed on the website, in particular the use of URLs to define queries rather than the traditional z39.50 indexSet.indexID format. Given that our existing system already specifies queries using RDF URIs it makes sense to mirror this in the specification of SRW queries. It also would seem to be good practice to work with URLs in a web service environment. There is already a published RDF schema for Bib-1 (http://www.gils.net/z-tokens.rdfs) which could be referenced by all SRW Servers. 

We have had also had to give thought to specifying queries and returning records which consist of more that simple text - in ARTISTE every record consists of an image and related metadata and queries may consist of only an image, only metadata, or a combination of a image and metadata. The easy way to achieve this is simply to pass the URI of the image as a string in the XML message but this has the consequence of requiring all users to have access to a web server where they can publish their query image. The better, but more, complex solution is to use the SOAP with Attachments specification to send the image itself which is then referenced from the message. Has anyone had any experience implementing SRW using SOAP with Attachments they would like to share? 

Unfortunately I could not attend the ZIG meeting at the beginning of the month but I look forward to reading the output.

Best Regards

Alison

Alison Stevenson
IT Innovation Centre
2 Venture Road
Chilworth Science Park
Southampton SO16 7NP 
 
Tel: +44 23 8076 0834
Fax: +44 23 8076 0833

mailto:as@it-innovation.soton.ac.uk
http://www.it-innovation.soton.ac.uk

Received on Thursday, 25 April 2002 08:21:12 UTC