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Z39.50. A Basic Introduction Kathleen R. Murray, Ph.D. William E. Moen, Ph.D. May 2002. Z39.50 Standards. International Standard, ISO 23950: “Information Retrieval (Z39.50): Application Service Definition and Protocol Specification” US National Standard, ANSI/NISO Z39.50.
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Z39.50 A Basic Introduction Kathleen R. Murray, Ph.D. William E. Moen, Ph.D. May 2002
Z39.50 Standards • International Standard, ISO 23950: “Information Retrieval (Z39.50): Application Service Definition and Protocol Specification” • US National Standard, ANSI/NISO Z39.50 “The standard specifies a client/server-based protocol for searching and retrieving information from remote databases.” Source: http://www.loc.gov/z3950/agency/ UNT Center for Digital Knowledge
Definition Z39.50 is a protocol which specifies data structures and interchange rules that allow a client machine (called an "origin" in the standard) to search databases on a server machine (called a "target" in the standard) and retrieve records that are identified as a result of such a search. - Clifford Lynch Source: http://www.dlib.org/dlib/april97/04lynch.html UNT Center for Digital Knowledge
Client-Server Model • The overall search and retrieval functions are split between the client and server • Z39.50 Client is called the "Origin“ • Z39.50 Server is called the “Target” Server = “Target” Client = “Origin” UNT Center for Digital Knowledge
Client-Server Model • User • Enters query in local system • Z39.50 Client • Translates query into Z39.50 format • Sends query to a Z39.50 server • Z39.50 Server • Presents the query to database system • Returns the results to client Database Server: Manages Data Z39.50 Server: Queries Database & Returns Results Z39.50 Client: Translates & Sends Query UNT Center for Digital Knowledge
Z39.50 Client • Part of the local computing system • Functions • Initiating a search • Sending a query • Requesting the return of records Major Benefit: User only has to know one set of search commands for local and remote searches. Client = “Origin” UNT Center for Digital Knowledge
Z39.50 Client Types • Integrated with OPAC • Allows staff and patrons to search other catalogs via Z39.50 • Stand-alone • Allows staff and patrons to search other catalogs and databases via Z39.50 UNT Center for Digital Knowledge
Z39.50 Server • Functions • Interfaces with remote databases • Responds to messages received from “Origin” or client systems Example: Provides client records that match a search query Server = “Target” UNT Center for Digital Knowledge
Virtual Catalog Example Single user search as multiple queries to multiple catalogs Z39.50Client ZServer Catalog 1 ZClient ZServer Catalog 2 ZServer Catalog 3 ZServer Catalog 4 ZServer Catalog N Resulting Virtual Catalog UserInterface User conducts single search to single logical resource UNT Center for Digital Knowledge
Learn more about client - server architecture by viewing the tutorial! Thanks! UNT Center for Digital Knowledge