# Presentation: 888331

## It’s Distributed searching, Jim

- But not as you know it!
- ZIG meeting, Leuven
- July 12th, 2000
- Bert Degenhart Drenth
- ADLIB Information Systems BV
- _[bert](mailto:bert@nl.adlibsoft.com)__[@](mailto:bert@nl.adlibsoft.com)__[nl](mailto:bert@nl.adlibsoft.com)__[.](mailto:bert@nl.adlibsoft.com)__[adlibsoft](mailto:bert@nl.adlibsoft.com)__[.com](mailto:bert@nl.adlibsoft.com)_
- _[http://www.](http://www.nl.adlibsoft.com/)__[nl](http://www.nl.adlibsoft.com/)__[.](http://www.nl.adlibsoft.com/)__[adlibsoft](http://www.nl.adlibsoft.com/)__[.com](http://www.nl.adlibsoft.com/)_

## A problem to be solved

- Multiple database architectures
- (ODBC, ADO, other)
- Use of standard components
- Use of standard protocols
- Distributed database
- Close to Web development
- Use for ‘cross domain’ application: library, museum and archives.

## An alternative architecture

- 3 functions
- Query through URL’s (get/post method)
- Return results in XML
- Use a broker or gateway to combine results

## A prototype:

- 2 databases: an ODBC source (MS-Access)an ADLIB database
- ODBC source contains simple ‘library’ records
- ADLIB database contains Dublin Core records

## System setup:

- ODBC source

- ADLIBdatabase

- translator

- translator

- ASP broker

- Web browser

- HTML

- url

- url

- url

- XML

- XML

- SQL

- TDS

- AQL

- records

## Technology used

- 1. Express query in URL (proprietary syntax)
- 2. Query is handed to translators by a HTTP request using Microsoft.XMLHTTP
- 3. Translators hand query to database engine using ODBC (ACCESS) or native calls
- 4. Translators return XML to broker
- 5. Broker uses XMLDOM to integrate results
- 6. Broker runs on ASP written in Jscript

## Comparison with Z39.50

- Differences:
- No BER
- No ‘library specific’ technology
- Current implementation does not split between search and retrieve
- No extended services

## Comparison with Z39.50

- Similarities
- Asynchronous searches possible
- For ‘real’ applications standardisation needs to take place on:
- Definition of query URL’s
- The three S-s : Syntax, Structure and Semantics
***Syntax : XML***
***Structure : return elements (DTD/schema)***
***Semantics : attribute set and profile***
- The mechanism for setting up this can be ‘borrowed’ from Z39.50

## Decouple transport mechanism from application

- Technology changes and is driven by forces outside of the library / museum / archive arena
- If you can’t beat them, join them
- Inertia (MARC is still there!)

## Developments in CIMI : what happened after the Z39.50 testbed

- Testbed proved that the technology worked, but no practical implementations are out there!
- No support for Z39.50 in commercial products

## Developments in CIMI : what happened after the Z39.50 testbed

- After the Z39.50 testbed the Dublin Core testbed was conducted.
- Proved to be successful, with a central repository.
- Support for DC in XML in commercial products.

## Developments in CIMI : what happened after the Z39.50 testbed...

- CIMI moved from DC to intra community data exchange, based on XML.
- MDA and CIMI are producing a DTD for Spectrum, scheduled for november 2000
- The CIMI Z39.50 profile could be used as a basis for distributed applications using HTTP technology, notably important:record schema (dtd / XML-schema)access points and semantics

## The end for Z39.50?

- My personal opinion : NO!
- Emphasis has to shift from ‘bits on the wire’ to the
- Three S-es for a variety of information services
- Integration, communication needs to take place with similar fields : TEI, EAD, Spectrum-XML and DC
- Of course: existing systems need upgrade / maintenance