ROADS and Z39.50
Searching ROADS servers using Z39.50 clients
The resource descriptions held in a ROADS database are normally made available using Whois++, a lightweight Internet search protocol. Whois++ is described in more detail in the ROADS Technical Specifications. However, in some situations it is desirable to make ROADS databases available to end-user client and intermediate systems that use the Z39.50 search and retrieve protocol. Z39.50 is a protocol that is often used to provide access to catalogues within the library, museum and archive communities.
This page describes some of the ways in which ROADS databases can be made available using Z39.50. Two approaches are outlined. Detailed descriptions of implementations of these two approaches are also available.
Z39.50 to Whois++ gateway
The first approach relies on a Z39.50 to Whois++ gateway. The gateway functions as a Z39.50 server, accepting queries from Z39.50 client systems. It converts them to Whois++ queries and passes them to the ROADS server. As results are returned by the ROADS server, they are converted into a suitable format for use by Z39.50 client systems and returned to the client as a Z39.50 result set.
A Z39.50 to Whois++ gateway, known as ZEXI, has been developed as part of the ROADS project. It is based on the Isite Information System available from CNIDR. ZEXI returns simple, unstructured text-based records known as SUTRS.
Details about obtaining and using ZEXI are available:
Loading ROADS records into a Z39.50-based database
The second approach involves copying records from the ROADS database into some other database that has a Z39.50 interface. Typically, the records will require some form of conversion during the copying procedure. Candidate database systems include Isite (see above) and the Zebra System developed by Index Data.
The Zebra Z39.50 server can make converted ROADS records available in two structured formats (USMARC and GRS-1) and in an unstructured format (SUTRS).
Details about obtaining and using Zebra are available.
Finally, it is worth noting that commercial extensions to Isite are also available that allow it to load ROADS records directly. At the time of writing it is not clear if these extensions have been used anywhere. Details of these extensions are available: see the 'ROADS++' entry in the BSn Doctypes maintained by Basis Systeme netzwerk.Demonstrators
Demonstrations of the approaches outlined above are available on the UKOLN Experimental Z39.50 Servers page.Separate demonstartors of each approach will be developed in due course.
Maintained by:
Andy
Powell
Last updated: 12-June-1998
