From 5243917e35bcd84925e89f609d291658a188e45b Mon Sep 17 00:00:00 2001 From: Mike Taylor Date: Wed, 16 Oct 2002 20:33:31 +0000 Subject: [PATCH] rolling commit --- doc/examples.xml | 94 +++++++++++++++++++++++++++++++++++++++++++++----- doc/introduction.xml | 4 +-- doc/quickstart.xml | 3 +- 3 files changed, 89 insertions(+), 12 deletions(-) diff --git a/doc/examples.xml b/doc/examples.xml index f2af444..86d8c59 100644 --- a/doc/examples.xml +++ b/doc/examples.xml @@ -1,5 +1,5 @@ - + Example Configurations @@ -106,7 +106,7 @@ $ yaz-client tcp:@:9999 Connecting...Ok. - Z> find @attr 1=/GENUS/MEANING @and lizard earthquakes + Z> find @attr 1=/GENUS/SPECIES/AUTHOR/@name Wedel Number of hits: 1 Z> format xml Z> show 1 @@ -139,10 +139,89 @@ + - Example 2: Supporting Z39.50 Searches + Example 2: Supporting Interoperable Searches + The problem with the previous example is that you need to know the + structure of the documents in order to find them. For example, + when we wanted to know the genera for which Matt Wedel is an + author, we had to formulate a complex XPath + 1=/GENUS/SPECIES/AUTHOR/@name + which embodies the knowledge that author names are specified in the + name attribute of the + <AUTHOR> element, + which is inside the + <SPECIES> element, + which in turn is inside the top-level + <GENUS> element. + + + This is bad not just because it requires a lot of typing, but more + significantly because it ties searching semantics to the physical + structure of the searched records. You can't use the same search + specification to search two databases if their internal + representations are different. Consider an alternative dinosaur + database in which the records have author names specified + inside an <authorName> element directly + inside a top-level <taxon> element: then + you'd need to search for them using + 1=/taxon/authorName + + + How, then, can we build broadcasting Information Retrieval + applications that look for records in many different databases? + The Z39.50 protocol offers a powerful and general solution to this: + abstract ``access points''. In the Z39.50 model, an access point + is simply a point at which searches can be directed. Nothing is + said about implementation: in a given database, an access point + might be implemented as an index, a path into physical records, an + algorithm for interrogating relational tables or whatever works. + The key point is that the semantics of an access point are fixed + and well defined. + + + For convenience, access points are gathered into attribute + sets. For example, the BIB-1 attribute set is supposed to + contain bibliographic access points such as author, title, subject + and ISBN; the GEO attribute set contains access points pertaining + to geospatial information (bounding box, ###, etc.); the CIMI + attribute set contains access points to do with museum collections + (provenance, inscriptions, etc.) + + + In practice, the BIB-1 attribute set has tended to be a dumping + ground for all sorts of access points, so that, for example, it + includes some geospatial access points as well as strictly + bibliographic ones. Nevertheless, the key point is that this model + allows a layer of abstraction over the physical representation of + records in databases. + + + In the BIB-1 attribute set, an author search is represented by + access point 1003. (See + ) + So we need to configure our dinosaur database so that searches for + BIB-1 access point 1003 look the + name attribute of the + <AUTHOR> element, + inside the + <SPECIES> element, + inside the top-level + <GENUS> element. + + + This is a two-step process. First, we need to tell Zebra that we + want to support the BIB-1 attribute set. Then we need to tell it + which elements of its record pertain to access point 1003. + + + + + + + FIXME ### This needs more text - - +--> + Introduction @@ -317,14 +317,12 @@ to seek support there. Join by sending email to zebra-request@indexdata.dk. Put the word 'subscribe' in the body of the message. - Third, it's possible to buy a commercial support contract, with well defined service levels and response times, from Index Data. See - for details. diff --git a/doc/quickstart.xml b/doc/quickstart.xml index 2fa7ad9..b5478ea 100644 --- a/doc/quickstart.xml +++ b/doc/quickstart.xml @@ -1,10 +1,11 @@ - + Quick Start -- 1.7.10.4