Manifestations Z ISO TC46/WG4/SC /3 SR Z Z

Z “Future Services” Z “Future Service” Z “Facility”

Z Foreword “Future Services” List Databases List Access Points List Elements List Element Set List Element Sets

Z Foreword “Future Services” Explain –to allow an origin to obtain details of the target implementation, including databases available for searching, data elements in records of a specified database, element sets supported, elements within a specified element set, attribute sets supported, attributes supported within a supported attribute set, diagnostic sets, and record syntaxes.

Z “Explain Facility” Explain database – IR-Explain-1 accessed via Z39.50 Search and Present services Explain Attribute set – exp-1 Explain syntax

Z ISO TC46/WG4/SC /3 SR Z z

Contributors Makx Dekkers Liv Holm Cliff Lynch Mark Needleman Bob Waldstein Mark Hinnebusch Denis Lynch Ray Denenberg

Rationale (Denis Lynch 1997) Many clients don’t know their servers –Users point clients at new servers –Servers add or change databases & services Clients need dynamic information –Server hours of operation –Billing rates –Supported attribute combinations –Field labels

Target Info (D. Lynch) One TargetInfo record per server –Target name –database combinations –Message of the day –Contact and access information –Network addresses

Database Info One DatabaseInfo record per database –Database name –Databases that can be searched with this one –Databases that are subsets of this one –Attribute sets, syntaxes, schemas, query types... –Copyright and contact information

TagSetInfo – all tags defined in a tagset SchemaInfo –Mapping of tagset numbers to tagsets –The record structure RecordSyntaxInfo –describes the record structure AttributeSetInfo –lists every attribute

Attribute Details –May list patterns for legal combinations { { { Use, {4, 16, 24} }, { Structure, All } }, { { Use, 1001 }, { Structure, 2 } } }

Term Lists One TermListInfo per database, –lists “indexes” –link to TermListDetails –A title, for display to users –A search cost hint (optimized, expensive…) –Is it scannable TermListDetails

Term Lists TermListDetails: may apply to many databases –Attribute combinations that access this term list –More info about scanning –Sample terms

Element Specification ElementSetDetails for Element Set Names RetrievalRecordDetails for CompSpec –Mapping of schema elements to record elements

Sort Information Sort keys available for database Map of elements and attributes

Extended Services Supported services –Availability, cost… –Is package retained in ES database? –Can ES be executed synchronously?

Category List Explain categories supported –Dynamically discover what can be dynamically discovered

Miscellaneous Complexities AccessInfo TermList titles for access points Or Use attributes from AttributeCombinations AssociatedDBs SubDBs supports “more specific” function PerElementDetails for field labels ProcessingInformation

Issues Model –Search and retrieve from a Z39.50 database Complexities What Information does a client need?