AGRIS Multi-Host Search System: Using Dublin Core to homogenise distributed databases Frehiwot...

AGRIS Multi-Host Search System: Using Dublin Core to homogenise distributed databases

AGRIS Multi-Host Search System: Using Dublin Core to homogenise distributed databases

Frehiwot Fisseha

FAO/WAICENT

AGRIS/CARIS and Documentation Unit

Overview

* Background - AGRIS * Motivation for AGRIS -MHS * Vision * Challenges * Way forward * Components and arichtecture of the MHS

Background- AGRIS

AGRIS is the international information system for the agricultural science and technology.

AGRIS is a bibliographic database created by FAO in 1974 to facilitate information exchange and to identify world literature dealing with all aspects of agriculture

AGRIS is a co-operative system. 199 national, international and intergovernmental centres participate and submit about 14.000 records per month

The system collects bibliographic references (to date, about 3 million) to either conventional (journal articles, books) or non-conventional materials (sometimes called "grey literature" e.g. theses, reports, etc.), not available through ordinary commercial channels.

Http://www.fao.org/agris

Motivation for the AGRIS MHS

We have wide range of bibliographic information that should be included into the AGRIS database

Large components of the AGRIS database are existing national bibliographic databases like AGRICOLA and ELFIS.

• Some of the databases are searchable on the internet and need not be copied or reprocessed by FAO's AGRIS processing group.

Vision

AGRIS as a focal point of access for agricultural

information (bibliographic as well as full text) on distributed databases and information systems

uniform presentation of meta information

easily accessible information content

Challenges

Distributed databases

Databases are heterogeneous• different data structure

• different metadata information

Way Forward

Develop a search engine to make a parallel search on distributed databases (Outsource development-ZADI)

• develop XML wrapper for each co-operating database

Develop common meta elements to homogenise search result set (In-house)

Way forward (Contd.)Related activities

Develop and propose DC based meta data description for agricultural resources for the purpose of resource discovery and interoperability

– organise working group to work on proposing DC based standards (agricultural Dublin Core elements and qualifiers)

– draft specification for a DC based standard for describing document-like agricultural resources

– crosswalk for the existing databases (AGRIS, CARIS, FAO online Catalogue)

– posted on Agstandard mailing list for discussion and feed back

– work in progress to encode the standard with an XML framework (DTD, RDF)

ClientClient

AGRIS-ServerAGRIS-Server

DistributedDatabases


Request Search Result

Search ResultsRequests

The AGRIS MHS System

Wrapper Manager

Wrapper Manager

TransactionManager

TransactionManager



ClientClient

static pages dynamic pages

AGRIS-WWW-Server

Components of the AGRIS MHS

AGRIS-ServerAGRIS-Server ClientClient

1. Login (AGRIS Homepage) andrequest for the search form (HTTP)

2. Transmission of a static search form (HTML) including intelligent checks (Java-Script)

TransactionManager

TransactionManager

AGRIS-WWW-Server


AGRIS-ServerAGRIS-Server ClientClient

3. Input of search criteria includingthe searchable databasesand request sending (http)

AGRIS-WWW-Server


TransactionManager

TransactionManager

4. Request transmission to dynamically generate thesearch result page


TransactionManager

TransactionManager

WrapperManager

WrapperManager

5. Kernel activation and request transmissionincluding request syntax and search criteria (databases, fields, search pattern)



6. Distributed requests on distributed databases through IP (XML) 7. Search result

delivery (XML)

8. Compilation of one homogenous result set and delivery

Using AG-DC


TransactionManager

TransactionManager

ClientClient

9. Result set conversion (XML->HTML) and transmission

10. Request answering (HTML)

AGRIS-WWW-Server


Search Result in AG-DC format

WrapperManager

WrapperManager

TransactionManager

TransactionManager



ClientClientAGRIS-ServerAGRIS-Server

AGRIS-WWW-Server


AGRIS-KernelAGRIS-Kernel

XML Query GeneratorXML Query Generator XML Result Set Composer

XML Result Set Composer

8. Compilation and Transmission of onehomogen result set

TransactionManager

TransactionManager



Knowledge Base(Database - URL)

Knowledge Base(Database - URL)

6. Translation of the http requestinto a standardised XML query and delivery to the databases

7. Search result delivery (XML)

5. Kernel activation and request transmissionincluding request syntax and search criteria (databases, fields, search pattern)

ClientClient





Search ResultRequest


XML-Wrapper



Database-Kernel

Data, Indexes

Knowledge BaseAGRIS-XML

<-> local Schemes

6.1. Translation of the XML-Request into the database specific syntax, opening of a retrieval session and activation of the database kernel

6.2. Database search



With AG-DC elements




6.3. Search result in database specific syntax

6.4. Conversion into XML



XML-Wrapper

Database-Kernel

Data, Indexes

Knowledge BaseAGRIS-XML

<-> local Schemes

ClientClient





Search ResultRequest

http:/cfs.zadi.de

Thank you for your attention!

AGRIS Multi-Host Search System: Using Dublin Core to homogenise distributed databases Frehiwot...

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