+++ /dev/null
-<!doctype linuxdoc system>
-
-<!--
- $Id: zebra.sgml,v 1.47 2000-02-25 11:35:41 adam Exp $
--->
-
-<article>
-<title>Zebra Server - Administrators's Guide and Reference
-<author><htmlurl url="http://www.indexdata.dk/" name="Index Data">,
-<tt><htmlurl url="mailto:info@indexdata.dk" name="info@indexdata.dk"></>
-<date>$Revision: 1.47 $
-<abstract>
-
-
-The Zebra server combines a versatile fielded/free-text
-indexing/search engine with a Z39.50-1995 frontend to provide a powerful and flexible
-information mining tool. This document explains the procedure for
-installing and configuring Zebra, and outlines the possibilities
-for managing data and providing Z39.50
-services with the software. Zebra is a free version of the Index Data Z'mbol
-information system, and it excludes some functionality such as incremental
-database updating and support for large databases.
-</abstract>
-
-<toc>
-
-<sect>Introduction
-
-<sect1>Overview
-
-<p>
-Zebra is a fielded free-text indexing and retrieval engine with a
-Z39.50 frontend. You can use any commercial or freeware Z39.50 client
-to access data stored in Zebra.
-
-Zebra server can be used at the core of a Z39.50-based information retrieval
-framework. We're making
-the server available now to allow researchers and small organisations to
-share their information in the best possible way. We believe that Z39.50
-currently represents one of the best ways of sharing information with others, and
-we would like to encourage as many people as possible to do so.
-This document is a guide to using Zebra. It will tell you
-how to compile the software, and how to prepare your first database.
-It also explains how the server can be configured to give you the
-functionality that you need.
-
-If you find the software interesting, you should join the support
-mailing-list by sending email to <tt/zebra-request@indexdata.dk/.
-
-If you are interested in running a commercial service, if you wish to run large
-databases, or if you wish to make incremental updates to your databases even
-while users are accessing your system, then you might be interested in the Z'mbol
-Information Server which is available from <htmlurl
-url="http://www.indexdata.dk/zmbol/" name="Index Data"> or Fretwell-Downing
-Informatics. Z'mbol is a complete and supported package which offers many
-exciting possibilities that we have not been able to fit into this package.
-
-<sect1>Features
-
-<p>
-This is a list of some of the most important features of the
-system.
-
-<itemize>
-
-<item>
-Supports arbitrarily complex records - base input format is an
-XML-like syntax which allows nested (structured) data elements, as
-well as variant forms of data.
-
-<item>
-Supports random storage formats. A system of input filters driven by
-regular expressions allows you to easily process most ASCII-based
-data formats. SGML/XML, ISO2709 (MARC), and raw text are also supported.
-
-<item>
-Supports boolean queries as well as relevance-ranking (free-text)
-searching. Right truncation and masking in terms are supported, as
-well as full regular expressions.
-
-<item>
-Supports multiple concrete syntaxes
-for record exchange (depending on the configuration): GRS-1, SUTRS,
-ISO2709 (*MARC), XML. Records can be mapped between record syntaxes and
-schema on the fly.
-
-<item>
-Supports approximate matching in registers (ie. spelling mistakes,
-etc).
-
-<item> Supports a subset of the Z39.50 Explain Facility. Zebra's Explain database
-is automatically updated when a set of records is loaded into Zebra.
-
-</itemize>
-
-<p>
-Protocol support:
-
-<itemize>
-
-<item>
-Protocol facilities: Init, Search, Retrieve, Browse, Sort, Close, and Explain.
-
-<item>
-Piggy-backed presents are honored in the search-request.
-
-<item>
-Named result sets are supported.
-
-<item>
-Easily configured to support different application profiles, with
-tables for attribute sets, tag sets, and abstract syntaxes.
-Additional tables control facilities such as element mappings to
-different schema (eg., GILS-to-USMARC).
-
-<item>
-Complex composition specifications using Espec-1 are partially
-supported (simple element requests only).
-
-<item>
-Element Set Names are defined using the Espec-1 capability of the
-system, and are given in configuration files as simple element
-requests (and possibly variant requests).
-
-<item>
-Zebra runs on most Unix-like systems as well as Windows NT - a binary
-distribution for Windows NT is forthcoming - so far, the installation
-requires Microsoft Visual C++ to compile the system (we use version 6.0).
-
-</itemize>
-
-<sect1>Future Work
-
-<p>
-
-These are some of the plans that we have for the software in the near
-and far future, approximately ordered after their relative importance.
-Items marked with an
-asterisk will be implemented before the
-last beta release.
-
-<itemize>
-
-<item>
-*Complete the support for variants.
-
-<item>
-*Finalize the data element <it/include/ facility to support multimedia
-data elements in records.
-
-<item>
-Add more sophisticated relevance ranking mechanisms. Add support for soundex
-and stemming. Add relevance <it/feedback/ support.
-
-<item>
-Complete EXPLAIN support.
-
-<item>
-We want to add a management system that allows you to
-control your databases and configuration tables from a graphical
-interface. We'll probably use Tcl/Tk to stay platform-independent.
-
-</itemize>
-
-Programmers thrive on user feedback. If you are interested in a facility that
-you don't see mentioned here, or if there's something you think we
-could do better, please drop us a mail. If you think it's all really
-neat, you're welcome to drop us a line saying that, too. You'll find
-contact info at the end of this file.
-
-<sect>Compiling the software
-<p>
-You need the
-<bf><htmlurl url="http://www.indexdata.dk/yaz/" name="YAZ"></>
-package in order to compile this software. We suggest you
-unpack <bf/YAZ/ in the same directory as Zebra. Running
-./configure (UNIX Only) and running make (nmake on WIN32) is
-in usully what it takes to compile YAZ.
-
-<sect1>UNIX
-<p>
-An ANSI C compiler is required to compile the Zebra
-server system — <tt/gcc/ works very well if your own system doesn't
-provide an adequate compiler.
-
-Unpack the distribution archive. The <tt>configure</tt> shell script
-attempts to guess correct values for various system-dependent variables
-used during compilation. It uses those values to create a 'Makefile' in
-each directory of Zebra.
-
-To run the configure script type:
-<tscreen><verb>
- ./configure
-</verb></tscreen>
-
-The configure script attempts to use the C compiler specified by
-the <tt>CC</tt> environment variable. If not set, GNU C
-will be used if it is available. The <tt>CFLAGS</tt> environment variable
-holds options to be passed to the C compiler. If you're using a
-Bourne-compatible shell you may pass something like this:
-<tscreen><verb>
- CC=/opt/ccs/bin/cc CFLAGS=-O ./configure
-</verb></tscreen>
-
-To customize Zebra the configure script accepts a set of options. The
-most important are
-<descrip>
-<tag><tt>-</tt><tt>-prefix </tt>path</tag> Specifies installation prefix. This is
-only needed if you run <tt>make install</tt> later to perform a
-"system" installation. The prefix is <tt>/usr/local</tt> if not
-specified.
-<tag><tt>-</tt><tt>-with-tclconfig=</tt>DIR</tag> If Tcl is installed on
-the system you can tell configure in which directory Tcl's
-<tt>tclConfig.sh</tt> is stored. The <tt>tclConfig.sh</tt> include
-information about settings required to link with Tcl's libraries.
-If you don't specify this option, configure will see if Tcl's shell
-<tt>tclsh</tt> is in your path and if it is, it will guess where
-the equivalent tclConfig.sh is located. If tclsh is not found in
-your path and this option is not given Zebra will not include Tcl support.
-<tag><tt>-</tt><tt>-with-yazconfig=</tt>DIR</tag> This options allows you to
-specify the directory that contains YAZ's <tt>yaz-config</tt>.
-This options is useful if you wish to compile Zebra with a specific
-version of YAZ. YAZ version 1.5 and later creates a script
-<tt>yaz-config</tt> that includes information on compiler settings
-needed to link with it.
-</descrip>
-
-When configured build the software by typing:
-<tscreen><verb>
- make
-</verb></tscreen>
-
-As an option you may type <tt>make depend</tt> to create
-source file dependencies for the package. This is only needed,
-however, if you modify the source code later.
-
-If successful, two executables have been created in the sub-directory
-<tt>bin</tt>.
-<descrip>
-<tag><tt>zebrasrv</tt></tag> The Z39.50 server and search engine.
-<tag><tt>zebraidx</tt></tag> The administrative tool for the search index.
-</descrip>
-
-<p>
-The next step is optional and is only needed if you wish to install
-zebra in system directories such as /usr/bin, /usr/lib, etc.
-
-To perform this step, type
-<tscreen><verb>
- make install
-</verb></tscreen>
-
-The executables will be installed in prefix/bin, and profile
-tables will be installed in prefix/lib/zebra/tab. Here prefix
-represents the prefix as specified -- default being /usr/local.
-
-<sect1>WIN32
-
-<p>
-Zebra is shipped with "makefiles" for the NMAKE tool that comes
-with Visual C++.
-
-Start an MS-DOS prompt and switch the sub directory <tt>WIN</tt> where
-the file <tt>makefile</tt> is located. Customize the installation
-by editing the <tt>makefile</tt> file (for example by using wordpad).
-
-The following summarises the most important settings in that file.
-
-<descrip>
-<tag><tt>YAZDIR</tt></tag> Specifies where YAZ is located.
-<tag><tt>DEBUG</tt></tag> If set to 1, the software is
-compiled with debugging libraries. If set to 0, the software
-is compiled with release (non-debugging) libraries.
-<tag>BZIP2</tag> A group of settings (<tt>BZIP2LIB</tt>,..)
-that must be defined if BZIP2 compression support is desired.
-</descrip>
-
-When satisfied with the settings in the makefile type
-<tscreen><verb>
-nmake
-</verb></tscreen>
-
-If compilation was successful the executables <tt>zebraidx.exe</tt>
-and <tt>zebrasrv.exe</tt> are put in the sub directory <tt>BIN</tt>.
-
-<sect>Quick Start
-<p>
-In this section, we will test the system by indexing a small set of sample
-GILS records that are included with the software distribution. Go to the
-<tt>test/gils</tt> subdirectory of the distribution archive. There you will
-find a configuration
-file named <tt>zebra.cfg</tt> with the following contents:
-<tscreen><verb>
-# Where the schema files, attribute files, etc. are located.
-profilePath: .:../../tab:../../../yaz/tab
-
-# Files that describe the attribute sets supported.
-attset: explain.att
-attset: bib1.att
-attset: gils.att
-</verb></tscreen>
-
-Now, edit the file and set <tt>profilePath</tt> to the path of the
-YAZ profile tables (sub directory <tt>tab</tt> of the YAZ distribution
-archive).
-
-The 48 test records are located in the sub directory <tt>records</tt>.
-To index these, type:
-<tscreen><verb>
-$ ../../bin/zebraidx -t grs.sgml update records
-</verb></tscreen>
-
-In the command above the option <tt>-t</tt> specified the record
-type — in this case <tt>grs.sgml</tt>. The word <tt>update</tt> followed
-by a directory root updates all files below that directory node.
-
-If your indexing command was successful, you are now ready to
-fire up a server. To start a server on port 2100, type:
-<tscreen><verb>
-$ ../../bin/zebrasrv tcp:@:2100
-</verb></tscreen>
-
-The Zebra index that you have just created has a single database
-named <tt/Default/. The database contains records structured according to
-the GILS profile, and the server will
-return records in either either XML, USMARC, GRS-1, or SUTRS depending
-on what your client asks for.
-
-To test the server, you can use any Z39.50 client (1992 or later). For
-instance, you can use the demo client that comes with YAZ: Just cd to
-the <tt/client/ subdirectory of the YAZ distribution and type:
-
-<tscreen><verb>
-$ ./yaz-client tcp:localhost:2100
-</verb></tscreen>
-
-When the client has connected, you can type:
-
-<tscreen><verb>
-Z> find surficial
-Z> show 1
-</verb></tscreen>
-
-The default retrieval syntax for the client is USMARC. To try other
-formats for the same record, try:
-
-<tscreen><verb>
-Z>format sutrs
-Z>show 1
-Z>format grs-1
-Z>show 1
-Z>format xml
-Z>show 1
-Z>elements B
-Z>show 1
-</verb></tscreen>
-
-<it>NOTE: You may notice that more fields are returned when your
-client requests SUTRS or GRS-1 records. When retrieving GILS records,
-this is normal - not all of the GILS data elements have mappings in
-the USMARC record format.</it>
-
-If you've made it this far, there's a good chance that
-you've got through the compilation OK.
-
-<sect>Administrating Zebra<label id="administrating">
-
-<p>
-
-To administrate Zebra, you run the
-<tt>zebraidx</tt> program. This program supports a number of options
-which are preceded by a minus, and a few commands (not preceded by
-minus).
-
-Both the Zebra administrative tool and the Z39.50 server share a
-set of index files and a global configuration file. The
-name of the configuration file defaults to <tt>zebra.cfg</tt>.
-The configuration file includes specifications on how to index
-various kinds of records and where the other configuration files
-are located. <tt>zebrasrv</tt> and <tt>zebraidx</tt> <em>must</em>
-be run in the directory where the configuration file lives unless you
-indicate the location of the configuration file by option
-<tt>-c</tt>.
-
-<sect1>Record Types<label id="record-types">
-<p>
-Indexing is a per-record process. Before a record is indexed search
-keys are extracted from whatever might be the layout the original
-record (sgml,html,text, etc..).
-The Zebra system currently supports two fundamantal types of records:
-structured and simple text.
-To specify a particular extraction process, use either the
-command line option <tt>-t</tt> or specify a
-<tt>recordType</tt> setting in the configuration file.
-
-<sect1>The Zebra Configuration File<label id="configuration-file">
-<p>
-The Zebra configuration file, read by <tt>zebraidx</tt> and
-<tt>zebrasrv</tt> defaults to <tt>zebra.cfg</tt> unless specified
-by <tt>-c</tt> option.
-
-You can edit the configuration file with a normal text editor.
-Parameter names and values are seperated by colons in the file. Lines
-starting with a hash sign (<tt/#/) are treated as comments.
-
-If you manage different sets of records that share common
-characteristics, you can organize the configuration settings for each
-type into &dquot;groups&dquot;.
-When <tt>zebraidx</tt> is run and you wish to address a given group
-you specify the group name with the <tt>-g</tt> option. In this case
-settings that have the group name as their prefix will be used
-by <tt>zebraidx</tt>. If no <tt/-g/ option is specified, the settings
-with no prefix are used.
-
-In the configuration file, the group name is placed before the option
-name itself, separated by a dot (.). For instance, to set the record type
-for group <tt/public/ to <tt/grs.sgml/ (the SGML-like format for structured
-records) you would write:
-
-<tscreen><verb>
-public.recordType: grs.sgml
-</verb></tscreen>
-
-To set the default value of the record type to <tt/text/ write:
-
-<tscreen><verb>
-recordType: text
-</verb></tscreen>
-
-The available configuration settings are summarized below. They will be
-explained further in the following sections.
-
-<descrip>
-<tag><it>group</it>.recordType[<it>.name</it>]</tag>
- Specifies how records with the file extension <it>name</it> should
- be handled by the indexer. This option may also be specified
- as a command line option (<tt>-t</tt>). Note that if you do not
- specify a <it/name/, the setting applies to all files. In general,
- the record type specifier consists of the elements (each
- element separated by dot), <it>fundamental-type</it>,
- <it>file-read-type</it> and arguments. Currently, two
- fundamental types exist, <tt>text</tt> and <tt>grs</tt>.
- <tag><it>group</it>.recordId</tag>
- Specifies how the records are to be identified when updated. See
-section <ref id="locating-records" name="Locating Records">.
-<tag><it>group</it>.database</tag>
- Specifies the Z39.50 database name.
-<tag><it>group</it>.storeKeys</tag>
- Specifies whether key information should be saved for a given
- group of records. If you plan to update/delete this type of
- records later this should be specified as 1; otherwise it
- should be 0 (default), to save register space.
-<tag><it>group</it>.storeData</tag>
- Specifies whether the records should be stored internally
- in the Zebra system files. If you want to maintain the raw records yourself,
- this option should be false (0). If you want Zebra to take care of the records
- for you, it should be true(1).
-<tag>lockDir</tag>
- Directory in which various lock files are stored.
-<tag>keyTmpDir</tag>
- Directory in which temporary files used during zebraidx' update
- phase are stored.
-<tag>setTmpDir</tag>
- Specifies the directory that the server uses for temporary result sets.
- If not specified <tt>/tmp</tt> will be used.
-<tag>profilePath</tag>
- Specifies the location of profile specification files.
-<tag>attset</tag>
- Specifies the filename(s) of attribute set files for use in
- searching. At least the Bib-1 set should be loaded (<tt/bib1.att/).
- The <tt/profilePath/ setting is used to look for the specified files.
- See section <ref id="attset-files" name="The Attribute Set Files">
-<tag>memMax</tag>
- Specifies size of internal memory to use for the zebraidx program. The
- amount is given in megabytes - default is 4 (4 MB).
-</descrip>
-<sect1>Locating Records<label id="locating-records">
-<p>
-The default behaviour of the Zebra system is to reference the
-records from their original location, i.e. where they were found when you
-ran <tt/zebraidx/. That is, when a client wishes to retrieve a record
-following a search operation, the files are accessed from the place
-where you originally put them - if you remove the files (without
-running <tt/zebraidx/ again, the client will receive a diagnostic
-message.
-
-If your input files are not permanent - for example if you retrieve
-your records from an outside source, or if they were temporarily
-mounted on a CD-ROM drive,
-you may want Zebra to make an internal copy of them. To do this,
-you specify 1 (true) in the <tt>storeData</tt> setting. When
-the Z39.50 server retrieves the records they will be read from the
-internal file structures of the system.
-
-<sect1>Indexing example
-
-<p>
-Consider a system in which you have a group of text files called
-<tt>simple</tt>. That group of records should belong to a Z39.50 database
-called <tt>textbase</tt>. The following <tt/zebra.cfg/ file will suffice:
-
-<tscreen><verb>
-profilePath: /usr/lib/yaz/tab:/usr/lib/zebra/tab
-attset: explain.att
-attset: bib1.att
-simple.recordType: text
-simple.database: textbase
-</verb></tscreen>
-
-<sect>Running the Maintenance Interface (zebraidx)
-
-<p>
-The following is a complete reference to the command line interface to
-the <tt/zebraidx/ application.
-
-<bf/Syntax/
-<tscreen><verb>
-$ zebraidx [options] command [directory] ...
-</verb></tscreen>
-<bf/Options/
-<descrip>
-<tag>-t <it/type/</tag>Update all files as <it/type/. Currently, the
-types supported are <tt/text/ and <tt/grs/<it/.subtype/. If no
-<it/subtype/ is provided for the GRS (General Record Structure) type,
-the canonical input format is assumed (see section <ref
-id="local-representation" name="Local Representation">). Generally, it
-is probably advisable to specify the record types in the
-<tt/zebra.cfg/ file (see section <ref id="record-types" name="Record
-Types">), to avoid confusion at subsequent updates.
-
-<tag>-c <it/config-file/</tag>Read the configuration file
-<it/config-file/ instead of <tt/zebra.cfg/.
-
-<tag>-g <it/group/</tag>Update the files according to the group
-settings for <it/group/ (see section <ref id="configuration-file"
-name="The Zebra Configuration File">).
-
-<tag>-d <it/database/</tag>The records located should be associated
-with the database name <it/database/ for access through the Z39.50
-server.
-
-<tag>-m <it/mbytes/</tag>Use <it/mbytes/ of megabytes before flushing
-keys to background storage. This setting affects performance when
-updating large databases.
-
-<tag>-s</tag>Show analysis of the indexing process. The maintenance
-program works in a read-only mode and doesn't change the state
-of the index. This options is very useful when you wish to test a
-new profile.
-
-<tag>-V</tag>Show Zebra version.
-
-<tag>-v <it/level/</tag>Set the log level to <it/level/. <it/level/
-should be one of <tt/none/, <tt/debug/, and <tt/all/.
-
-</descrip>
-
-<bf/Commands/
-<descrip>
-<tag>Update <it/directory/</tag>Update the register with the files
-contained in <it/directory/. If no directory is provided, a list of
-files is read from <tt/stdin/. See section <ref
-id="administrating" name="Administrating Zebra">.
-
-</descrip>
-
-<sect>The Z39.50 Server
-
-<sect1>Running the Z39.50 Server (zebrasrv)
-
-<p>
-<bf/Syntax/
-<tscreen><verb>
-zebrasrv [options] [listener-address ...]
-</verb></tscreen>
-
-<bf/Options/
-<descrip>
-<tag>-a <it/APDU file/</tag> Specify a file for dumping PDUs (for diagnostic purposes).
-The special name &dquot;-&dquot; sends output to <tt/stderr/.
-
-<tag>-c <it/config-file/</tag> Read configuration information from <it/config-file/. The default configuration is <tt>./zebra.cfg</tt>.
-
-<tag/-S/Don't fork on connection requests. This can be useful for
-symbolic-level debugging. The server can only accept a single
-connection in this mode.
-
-<tag>-l <it/logfile/</tag>Specify an output file for the diagnostic
-messages. The default is to write this information to <tt/stderr/.
-
-<tag>-v <it/log-level/</tag>The log level. Use a comma-separated list of members of the set
-{fatal,debug,warn,log,all,none}.
-
-<tag>-u <it/username/</tag>Set user ID. Sets the real UID of the server process to that of the
-given <it/username/. It's useful if you aren't comfortable with having the
-server run as root, but you need to start it as such to bind a
-privileged port.
-
-<tag>-w <it/working-directory/</tag>Change working directory.
-
-<tag>-i</tag>Run under the Internet superserver, <tt/inetd/. Make
-sure you use the logfile option <tt/-l/ in conjunction with this
-mode and specify the <tt/-l/ option before any other options.
-
-<tag>-t <it/timeout/</tag>Set the idle session timeout (default 60 minutes).
-
-<tag>-k <it/kilobytes/</tag>Set the (approximate) maximum size of
-present response messages. Default is 1024 Kb (1 Mb).
-</descrip>
-
-A <it/listener-address/ consists of a transport mode followed by a
-colon (:) followed by a listener address. The transport mode is
-either <tt/osi/ or <tt/tcp/.
-
-For TCP, an address has the form
-
-<tscreen><verb>
-hostname | IP-number [: portnumber]
-</verb></tscreen>
-
-The port number defaults to 210 (standard Z39.50 port).
-
-The special hostname &dquot;@&dquot; is mapped to
-the address INADDR_ANY, which causes the server to listen on any local
-interface. To start the server listening on the registered port for
-Z39.50, and to drop root privileges once the
-port is bound, execute the server like this (from a root shell):
-
-<tscreen><verb>
-zebrasrv -u daemon tcp:@
-</verb></tscreen>
-
-You can replace <tt/daemon/ with another user, eg. your own account, or
-a dedicated IR server account.
-
-The default behavior for <tt/zebrasrv/ is to establish a single TCP/IP
-listener, for the Z39.50 protocol, on port 9999.
-
-<sect1>Z39.50 Protocol Support and Behavior
-
-<sect2>Initialization
-
-<p>
-During initialization, the server will negotiate to version 3 of the
-Z39.50 protocol (unless the client specifies a lower version), and the option bits for Search, Present, Scan,
-NamedResultSets, and concurrentOperations will be set, if requested by
-the client. The maximum PDU size is negotiated down to a maximum of
-1Mb by default.
-
-<sect2>Search<label id="search">
-
-<p>
-The supported query type are 1 and 101. All operators are currently
-supported with the restriction that only proximity units of type "word" are
-supported for the proximity operator.
-Queries can be arbitrarily complex.
-Named result sets are supported, and result sets can be used as operands
-without limitations.
-Searches may span multiple databases.
-
-The server has full support for piggy-backed present requests (see
-also the following section).
-
-<bf/Use/ attributes are interpreted according to the attribute sets which
-have been loaded in the <tt/zebra.cfg/ file, and are matched against
-specific fields as specified in the <tt/.abs/ file which describes the
-profile of the records which have been loaded. If no <bf/Use/
-attribute is provided, a default of Bib-1 <bf/Any/ is assumed.
-
-If a <bf/Structure/ attribute of <bf/Phrase/ is used in conjunction with a
-<bf/Completeness/ attribute of <bf/Complete (Sub)field/, the term is
-matched against the contents of the phrase (long word) register, if one
-exists for the given <bf/Use/ attribute.
-A phrase register is created for those fields in the <tt/.abs/
-file that contains a <tt/p/-specifier.
-
-If <bf/Structure/=<bf/Phrase/ is used in conjunction with
-<bf/Incomplete Field/ - the default value for <bf/Completeness/, the
-search is directed against the normal word registers, but if the term
-contains multiple words, the term will only match if all of the words
-are found immediately adjacent, and in the given order.
-The word search is performed on those fields that are indexed as
-type <tt/w/ in the <tt/.abs/ file.
-
-If the <bf/Structure/ attribute is <bf/Word List/,
-<bf/Free-form Text/, or <bf/Document Text/, the term is treated as a
-natural-language, relevance-ranked query.
-This search type uses the word register, i.e. those fields
-that are indexed as type <tt/w/ in the <tt/.abs/ file.
-
-If the <bf/Structure/ attribute is <bf/Numeric String/ the
-term is treated as an integer. The search is performed on those
-fields that are indexed as type <tt/n/ in the <tt/.abs/ file.
-
-If the <bf/Structure/ attribute is <bf/URx/ the
-term is treated as a URX (URL) entity. The search is performed on those
-fields that are indexed as type <tt/u/ in the <tt/.abs/ file.
-
-If the <bf/Structure/ attribute is <bf/Local Number/ the
-term is treated as native Zebra Record Identifier.
-
-If the <bf/Relation/ attribute is <bf/Equals/ (default), the term is
-matched in a normal fashion (modulo truncation and processing of
-individual words, if required). If <bf/Relation/ is <bf/Less Than/,
-<bf/Less Than or Equal/, <bf/Greater than/, or <bf/Greater than or
-Equal/, the term is assumed to be numerical, and a standard regular
-expression is constructed to match the given expression. If
-<bf/Relation/ is <bf/Relevance/, the standard natural-language query
-processor is invoked.
-
-For the <bf/Truncation/ attribute, <bf/No Truncation/ is the default.
-<bf/Left Truncation/ is not supported. <bf/Process #/ is supported, as
-is <bf/Regxp-1/. <bf/Regxp-2/ enables the fault-tolerant (fuzzy)
-search. As a default, a single error (deletion, insertion,
-replacement) is accepted when terms are matched against the register
-contents.
-
-<sect3>Regular expressions
-<p>
-
-Each term in a query is interpreted as a regular expression if
-the truncation value is either <bf/Regxp-1/ (102) or <bf/Regxp-2/ (103).
-Both query types follow the same syntax with the operands:
-<descrip>
-<tag/x/ Matches the character <it/x/.
-<tag/./ Matches any character.
-<tag><tt/[/..<tt/]/</tag> Matches the set of characters specified;
- such as <tt/[abc]/ or <tt/[a-c]/.
-</descrip>
-and the operators:
-<descrip>
-<tag/x*/ Matches <it/x/ zero or more times. Priority: high.
-<tag/x+/ Matches <it/x/ one or more times. Priority: high.
-<tag/x?/ Matches <it/x/ once or twice. Priority: high.
-<tag/xy/ Matches <it/x/, then <it/y/. Priority: medium.
-<tag/x|y/ Matches either <it/x/ or <it/y/. Priority: low.
-</descrip>
-The order of evaluation may be changed by using parentheses.
-
-If the first character of the <bf/Regxp-2/ query is a plus character
-(<tt/+/) it marks the beginning of a section with non-standard
-specifiers. The next plus character marks the end of the section.
-Currently Zebra only supports one specifier, the error tolerance,
-which consists one digit.
-
-Since the plus operator is normally a suffix operator the addition to
-the query syntax doesn't violate the syntax for standard regular
-expressions.
-
-<sect3>Query examples
-<p>
-
-Phrase search for <bf/information retrieval/ in the title-register:
-<verb>
- @attr 1=4 "information retrieval"
-</verb>
-
-Ranked search for the same thing:
-<verb>
- @attr 1=4 @attr 2=102 "Information retrieval"
-</verb>
-
-Phrase search with a regular expression:
-<verb>
- @attr 1=4 @attr 5=102 "informat.* retrieval"
-</verb>
-
-Ranked search with a regular expression:
-<verb>
- @attr 1=4 @attr 5=102 @attr 2=102 "informat.* retrieval"
-</verb>
-
-In the GILS schema (<tt/gils.abs/), the west-bounding-coordinate is
-indexed as type <tt/n/, and is therefore searched by specifying
-<bf/structure/=<bf/Numeric String/.
-To match all those records with west-bounding-coordinate greater
-than -114 we use the following query:
-<verb>
- @attr 4=109 @attr 2=5 @attr gils 1=2038 -114
-</verb>
-
-<sect2>Present
-<p>
-The present facility is supported in a standard fashion. The requested
-record syntax is matched against the ones supported by the profile of
-each record retrieved. If no record syntax is given, SUTRS is the
-default. The requested element set name, again, is matched against any
-provided by the relevant record profiles.
-
-<sect2>Scan
-
-<p>
-The attribute combinations provided with the TermListAndStartPoint are
-processed in the same way as operands in a query (see above).
-Currently, only the term and the globalOccurrences are returned with
-the TermInfo structure.
-
-<sect2>Sort
-
-<p>
-Z39.50 specifies three diffent types of sort criterias.
-Of these Zebra supports the attribute specification type in which
-case the use attribute specifies the "Sort register".
-Sort registers are created for those fields that are of type "sort" in
-the default.idx file.
-The corresponding character mapping file in default.idx specifies the
-ordinal of each character used in the actual sort.
-
-Z39.50 allows the client to specify sorting on one or more input
-result sets and one output result set.
-Zebra supports sorting on one result set only which may or may not
-be the same as the output result set.
-
-<sect2>Close
-
-<p>
-If a Close PDU is received, the server will respond with a Close PDU
-with reason=FINISHED, no matter which protocol version was negotiated
-during initialization. If the protocol version is 3 or more, the
-server will generate a Close PDU under certain circumstances,
-including a session timeout (60 minutes by default), and certain kinds of
-protocol errors. Once a Close PDU has been sent, the protocol
-association is considered broken, and the transport connection will be
-closed immediately upon receipt of further data, or following a short
-timeout.
-
-<sect>The Record Model
-
-<p>
-Zebra is designed to support a wide range of data management
-applications. The system can be configured to handle virtually any
-kind of structured data. Each record in the system is associated with
-a <it/record schema/ which lends context to the data elements of the
-record. Any number of record schema can coexist in the system.
-Although it may be wise to use only a single schema within
-one database, the system poses no such restrictions.
-
-The record model described in this chapter applies to the fundamental,
-structured
-record type <tt>grs</tt> as introduced in
-section <ref id="record-types" name="Record Types">.
-
-Records pass through three different states during processing in the
-system.
-
-<itemize>
-<item>When records are accessed by the system, they are represented
-in their local, or native format. This might be SGML or HTML files,
-News or Mail archives, MARC records. If the system doesn't already
-know how to read the type of data you need to store, you can set up an
-input filter by preparing conversion rules based on regular
-expressions and possibly augmented by a flexible scripting language (Tcl). The input filter
-produces as output an internal representation:
-
-<item>When records are processed by the system, they are represented
-in a tree-structure, constructed by tagged data elements hanging off a
-root node. The tagged elements may contain data or yet more tagged
-elements in a recursive structure. The system performs various
-actions on this tree structure (indexing, element selection, schema
-mapping, etc.),
-
-<item>Before transmitting records to the client, they are first
-converted from the internal structure to a form suitable for exchange
-over the network - according to the Z39.50 standard.
-</itemize>
-
-<sect1>Local Representation<label id="local-representation">
-
-<p>
-As mentioned earlier, Zebra places few restrictions on the type of
-data that you can index and manage. Generally, whatever the form of
-the data, it is parsed by an input filter specific to that format, and
-turned into an internal structure that Zebra knows how to handle. This
-process takes place whenever the record is accessed - for indexing and
-retrieval.
-
-<p>
-The RecordType parameter in the <tt/zebra.cfg/ file, or the <tt/-t/
-option to the indexer tells Zebra how to process input records. Two
-basic types of processing are available - raw text and structured
-data. Raw text is just that, and it is selected by providing the
-argument <bf/text/ to Zebra. Structured records are all handled
-internally using the basic mechanisms described in the subsequent
-sections. Zebra can read structured records in many different formats.
-How this is done is governed by additional parameters after the
-&dquot;grs&dquot; keyboard, separated by &dquot;.&dquot; characters.
-
-Three basic subtypes to the <bf/grs/ type are currently available:
-
-<descrip>
-<tag>grs.sgml</tag>This is the canonical input format —
-described below. It is a simple SGML-like syntax.
-
-<tag>grs.regx.<it/filter/</tag>This enables a user-supplied input
-filter. The mechanisms of these filters are described below.
-
-<tag>grs.tcl.<it/filter/</tag>This enables a user-supplied input
-filter with Tcl rules (only availble if zebra is compiled with Tcl
-support).
-
-<tag>grs.marc.<it/abstract syntax/</tag>This allows Zebra to read
-records in the ISO2709 (MARC) encoding standard. In this case, the
-last paramemeter <it/abstract syntax/ names the .abs file (see below)
-which describes the specific MARC structure of the input record as
-well as the indexing rules.
-</descrip>
-
-<sect2>Canonical Input Format
-
-<p>
-Although input data can take any form, it is sometimes useful to
-describe the record processing capabilities of the system in terms of
-a single, canonical input format that gives access to the full
-spectrum of structure and flexibility in the system. In Zebra, this
-canonical format is an &dquot;SGML-like&dquot; syntax.
-
-To use the canonical format specify <tt>grs.sgml</tt> as the record
-type,
-
-Consider a record describing an information resource (such a record is
-sometimes known as a <it/locator record/). It might contain a field
-describing the distributor of the information resource, which might in
-turn be partitioned into various fields providing details about the
-distributor, like this:
-
-<tscreen><verb>
-<Distributor>
- <Name> USGS/WRD &etago;Name>
- <Organization> USGS/WRD &etago;Organization>
- <Street-Address>
- U.S. GEOLOGICAL SURVEY, 505 MARQUETTE, NW
- &etago;Street-Address>
- <City> ALBUQUERQUE &etago;City>
- <State> NM &etago;State>
- <Zip-Code> 87102 &etago;Zip-Code>
- <Country> USA &etago;Country>
- <Telephone> (505) 766-5560 &etago;Telephone>
-&etago;Distributor>
-</verb></tscreen>
-
-<it>NOTE: The indentation used above is used to illustrate how Zebra
-interprets the markup. The indentation, in itself, has no
-significance to the parser for the canonical input format, which
-discards superfluous whitespace.</it>
-
-The keywords surrounded by <...> are <it/tags/, while the
-sections of text in between are the <it/data elements/. A data element
-is characterized by its location in the tree that is made up by the
-nested elements. Each element is terminated by a closing tag -
-beginning with <tt/&etago;/, and containing the same symbolic tag-name as
-the corresponding opening tag. The general closing tag - <tt/&etago;>/ -
-terminates the element started by the last opening tag. The
-structuring of elements is significant. The element <bf/Telephone/,
-for instance, may be indexed and presented to the client differently,
-depending on whether it appears inside the <bf/Distributor/ element,
-or some other, structured data element such a <bf/Supplier/ element.
-
-<sect3>Record Root
-
-<p>
-The first tag in a record describes the root node of the tree that
-makes up the total record. In the canonical input format, the root tag
-should contain the name of the schema that lends context to the
-elements of the record (see section <ref id="internal-representation"
-name="Internal Representation">). The following is a GILS record that
-contains only a single element (strictly speaking, that makes it an
-illegal GILS record, since the GILS profile includes several mandatory
-elements - Zebra does not validate the contents of a record against
-the Z39.50 profile, however - it merely attempts to match up elements
-of a local representation with the given schema):
-
-<tscreen><verb>
-<gils>
- <title>Zen and the Art of Motorcycle Maintenance&etago;title>
-&etago;gils>
-</verb></tscreen>
-
-<sect3>Variants
-
-<p>
-Zebra allows you to provide individual data elements in a number of
-<it/variant forms/. Examples of variant forms are textual data
-elements which might appear in different languages, and images which
-may appear in different formats or layouts. The variant system in
-Zebra is
-essentially a representation of the variant mechanism of
-Z39.50-1995.
-
-The following is an example of a title element which occurs in two
-different languages.
-
-<tscreen><verb>
-<title>
- <var lang lang "eng">
- Zen and the Art of Motorcycle Maintenance&etago;>
- <var lang lang "dan">
- Zen og Kunsten at Vedligeholde en Motorcykel&etago;>
-&etago;title>
-</verb></tscreen>
-
-The syntax of the <it/variant element/ is <tt><<bf/var/ <it/class
-type value/></tt>. The available values for the <it/class/ and
-<it/type/ fields are given by the variant set that is associated with the
-current schema (see section <ref id="variant-set" name="Variant Set
-File">).
-
-Variant elements are terminated by the general end-tag &etago;>, by
-the variant end-tag &etago;var>, by the appearance of another variant
-tag with the same <it/class/ and <it/value/ settings, or by the
-appearance of another, normal tag. In other words, the end-tags for
-the variants used in the example above could have been saved.
-
-Variant elements can be nested. The element
-
-<tscreen><verb>
-<title>
- <var lang lang "eng"><var body iana "text/plain">
- Zen and the Art of Motorcycle Maintenance
-&etago;title>
-</verb></tscreen>
-
-Associates two variant components to the variant list for the title
-element.
-
-Given the nesting rules described above, we could write
-
-<tscreen><verb>
-<title>
- <var body iana "text/plain>
- <var lang lang "eng">
- Zen and the Art of Motorcycle Maintenance
- <var lang lang "dan">
- Zen og Kunsten at Vedligeholde en Motorcykel
-&etago;title>
-</verb></tscreen>
-
-The title element above comes in two variants. Both have the IANA body
-type &dquot;text/plain&dquot;, but one is in English, and the other in
-Danish. The client, using the element selection mechanism of Z39.50,
-can retrieve information about the available variant forms of data
-elements, or it can select specific variants based on the requirements
-of the end-user.
-
-<sect2>Input Filters
-
-<p>
-In order to handle general input formats, Zebra allows the
-operator to define filters which read individual records in their native format
-and produce an internal representation that the system can
-work with.
-
-Input filters are ASCII files, generally with the suffix <tt/.flt/.
-The system looks for the files in the directories given in the
-<bf/profilePath/ setting in the <tt/zebra.cfg/ files. The record type
-for the filter is <tt>grs.regx.</tt><it>filter-filename</it>
-(fundamental type <tt>grs</tt>, file read type <tt>regx</tt>, argument
-<it>filter-filename</it>).
-
-Generally, an input filter consists of a sequence of rules, where each
-rule consists of a sequence of expressions, followed by an action. The
-expressions are evaluated against the contents of the input record,
-and the actions normally contribute to the generation of an internal
-representation of the record.
-
-An expression can be either of the following:
-
-<descrip>
-<tag/INIT/The action associated with this expression is evaluated
-exactly once in the lifetime of the application, before any records
-are read. It can be used in conjunction with an action that
-initializes tables or other resources that are used in the processing
-of input records.
-
-<tag/BEGIN/Matches the beginning of the record. It can be used to
-initialize variables, etc. Typically, the <bf/BEGIN/ rule is also used
-to establish the root node of the record.
-
-<tag/END/Matches the end of the record - when all of the contents
-of the record has been processed.
-
-<tag>/pattern/</tag>Matches a string of characters from the input
-record.
-
-<tag/BODY/This keyword may only be used between two patterns. It
-matches everything between (not including) those patterns.
-
-<tag/FINISH/THe expression asssociated with this pattern is evaluated
-once, before the application terminates. It can be used to release
-system resources - typically ones allocated in the <bf/INIT/ step.
-
-</descrip>
-
-An action is surrounded by curly braces ({...}), and consists of a
-sequence of statements. Statements may be separated by newlines or
-semicolons (;). Within actions, the strings that matched the
-expressions immediately preceding the action can be referred to as
-$0, $1, $2, etc.
-
-The available statements are:
-
-<descrip>
-
-<tag>begin <it/type [parameter ... ]/</tag>Begin a new
-data element. The type is one of the following:
-<descrip>
-<tag/record/Begin a new record. The followingparameter should be the
-name of the schema that describes the structure of the record, eg.
-<tt/gils/ or <tt/wais/ (see below). The <tt/begin record/ call should
-precede
-any other use of the <bf/begin/ statement.
-
-<tag/element/Begin a new tagged element. The parameter is the
-name of the tag. If the tag is not matched anywhere in the tagsets
-referenced by the current schema, it is treated as a local string
-tag.
-
-<tag/variant/Begin a new node in a variant tree. The parameters are
-<it/class type value/.
-
-</descrip>
-
-<tag/data/Create a data element. The concatenated arguments make
-up the value of the data element. The option <tt/-text/ signals that
-the layout (whitespace) of the data should be retained for
-transmission. The option <tt/-element/ <it/tag/ wraps the data up in
-the <it/tag/. The use of the <tt/-element/ option is equivalent to
-preceding the command with a <bf/begin element/ command, and following
-it with the <bf/end/ command.
-
-<tag>end <it/[type]/</tag>Close a tagged element. If no parameter is given,
-the last element on the stack is terminated. The first parameter, if
-any, is a type name, similar to the <bf/begin/ statement. For the
-<bf/element/ type, a tag name can be provided to terminate a specific tag.
-
-</descrip>
-
-The following input filter reads a Usenet news file, producing a
-record in the WAIS schema. Note that the body of a news posting is
-separated from the list of headers by a blank line (or rather a
-sequence of two newline characters.
-
-<tscreen><verb>
-BEGIN { begin record wais }
-
-/^From:/ BODY /$/ { data -element name $1 }
-/^Subject:/ BODY /$/ { data -element title $1 }
-/^Date:/ BODY /$/ { data -element lastModified $1 }
-/\n\n/ BODY END {
- begin element bodyOfDisplay
- begin variant body iana "text/plain"
- data -text $1
- end record
- }
-</verb></tscreen>
-
-If Zebra is compiled with support for Tcl (Tool Command Language)
-enabled, the statements described above are supplemented with a complete
-scripting environment, including control structures (conditional
-expressions and loop constructs), and powerful string manipulation
-mechanisms for modifying the elements of a record. Tcl is a popular
-scripting environment, with several tutorials available both online
-and in hardcopy.
-
-<it>NOTE: Variant support is not currently available in the input
-filter, but will be included with one of the next
-releases.</it>
-
-<sect1>Internal Representation<label id="internal-representation">
-
-<p>
-When records are manipulated by the system, they're represented in a
-tree-structure, with data elements at the leaf nodes, and tags or
-variant components at the non-leaf nodes. The root-node identifies the
-schema that lends context to the tagging and structuring of the
-record. Imagine a simple record, consisting of a 'title' element and
-an 'author' element:
-
-<tscreen><verb>
- TITLE "Zen and the Art of Motorcycle Maintenance"
-ROOT
- AUTHOR "Robert Pirsig"
-</verb></tscreen>
-
-A slightly more complex record would have the author element consist
-of two elements, a surname and a first name:
-
-<tscreen><verb>
- TITLE "Zen and the Art of Motorcycle Maintenance"
-ROOT
- FIRST-NAME "Robert"
- AUTHOR
- SURNAME "Pirsig"
-</verb></tscreen>
-
-The root of the record will refer to the record schema that describes
-the structuring of this particular record. The schema defines the
-element tags (TITLE, FIRST-NAME, etc.) that may occur in the record, as
-well as the structuring (SURNAME should appear below AUTHOR, etc.). In
-addition, the schema establishes element set names that are used by
-the client to request a subset of the elements of a given record. The
-schema may also establish rules for converting the record to a
-different schema, by stating, for each element, a mapping to a
-different tag path.
-
-<sect2>Tagged Elements
-
-<p>
-A data element is characterized by its tag, and its position in the
-structure of the record. For instance, while the tag &dquot;telephone
-number&dquot; may be used different places in a record, we may need to
-distinguish between these occurrences, both for searching and
-presentation purposes. For instance, while the phone numbers for the
-&dquot;customer&dquot; and the &dquot;service provider&dquot; are both
-representatives for the same type of resource (a telephone number), it
-is essential that they be kept separate. The record schema provides
-the structure of the record, and names each data element (defined by
-the sequence of tags - the tag path - by which the element can be
-reached from the root of the record).
-
-<sect2>Variants
-
-<p>
-The children of a tag node may be either more tag nodes, a data node
-(possibly accompanied by tag nodes),
-or a tree of variant nodes. The children of variant nodes are either
-more variant nodes or a data node (possibly accompanied by more
-variant nodes). Each leaf node, which is normally a
-data node, corresponds to a <it/variant form/ of the tagged element
-identified by the tag which parents the variant tree. The following
-title element occurs in two different languages:
-
-<tscreen><verb>
- VARIANT LANG=ENG "War and Peace"
-TITLE
- VARIANT LANG=DAN "Krig og Fred"
-</verb></tscreen>
-
-Which of the two elements are transmitted to the client by the server
-depends on the specifications provided by the client, if any.
-
-In practice, each variant node is associated with a triple of class,
-type, value, corresponding to the variant mechanism of Z39.50.
-
-<sect2>Data Elements
-
-<p>
-Data nodes have no children (they are always leaf nodes in the record
-tree).
-
-<it>NOTE: Documentation needs extension here about types of nodes - numerical,
-textual, etc., plus the various types of inclusion notes.</it>
-
-<sect1>Configuring Your Data Model<label id="data-model">
-
-<p>
-The following sections describe the configuration files that govern
-the internal management of data records. The system searches for the files
-in the directories specified by the <bf/profilePath/ setting in the
-<tt/zebra.cfg/ file.
-
-<sect2>About Object Identifers
-<p>
-When Object Identifiers (or OID's) need to be specified in the following
-a named OID reference or a raw OID reference may be used. For the named
-OID's refer to the source file <tt>util/oid.c</tt> from YAZ. The raw
-canonical OID's are specified in dot-notation (for example
-1.2.840.10003.3.1000.81.1).
-
-<sect2>The Abstract Syntax
-
-<p>
-The abstract syntax definition (also known as an Abstract Record
-Structure, or ARS) is the focal point of the
-record schema description. For a given schema, the ABS file may state any
-or all of the following:
-
-<itemize>
-<item>The object identifier of the Z39.50 schema associated
-with the ARS, so that it can be referred to by the client.
-
-<item>The attribute set (which can possibly be a compound of multiple
-sets) which applies in the profile. This is used when indexing and
-searching the records belonging to the given profile.
-
-<item>The Tag set (again, this can consist of several different sets).
-This is used when reading the records from a file, to recognize the
-different tags, and when transmitting the record to the client -
-mapping the tags to their numerical representation, if they are
-known.
-
-<item>The variant set which is used in the profile. This provides a
-vocabulary for specifying the <it/forms/ of data that appear inside
-the records.
-
-<item>Element set names, which are a shorthand way for the client to
-ask for a subset of the data elements contained in a record. Element
-set names, in the retrieval module, are mapped to <it/element
-specifications/, which contain information equivalent to the
-<it/Espec-1/ syntax of Z39.50.
-
-<item>Map tables, which may specify mappings to <it/other/ database
-profiles, if desired.
-
-<item>Possibly, a set of rules describing the mapping of elements to a
-MARC representation.
-
-<item>A list of element descriptions (this is the actual ARS of the
-schema, in Z39.50 terms), which lists the ways in which the various
-tags can be used and organized hierarchically.
-</itemize>
-
-Several of the entries above simply refer to other files, which
-describe the given objects.
-
-<sect2>The Configuration Files
-
-<p>
-This section describes the syntax and use of the various tables which
-are used by the retrieval module.
-
-The number of different file types may appear daunting at first, but
-each type corresponds fairly clearly to a single aspect of the Z39.50
-retrieval facilities. Further, the average database administrator,
-who is simply reusing an existing profile for which tables already
-exist, shouldn't have to worry too much about the contents of these tables.
-
-Generally, the files are simple ASCII files, which can be maintained
-using any text editor. Blank lines, and lines beginning with a (#) are
-ignored. Any characters on a line followed by a (#) are also ignored.
-All other
-lines contain <it/directives/, which provide some setting or value
-to the system. Generally, settings are characterized by a single
-keyword, identifying the setting, followed by a number of parameters.
-Some settings are repeatable (r), while others may occur only once in a
-file. Some settings are optional (o), whicle others again are
-mandatory (m).
-
-<sect2>The Abstract Syntax (.abs) Files
-
-<p>
-The name of this file type is slightly misleading in Z39.50 terms,
-since, apart from the actual abstract syntax of the profile, it also
-includes most of the other definitions that go into a database
-profile.
-
-When a record in the canonical, SGML-like format is read from a file
-or from the database, the first tag of the file should reference the
-profile that governs the layout of the record. If the first tag of the
-record is, say, <tt><gils></tt>, the system will look for the profile
-definition in the file <tt/gils.abs/. Profile definitions are cached,
-so they only have to be read once during the lifespan of the current
-process.
-
-When writing your own input filters, the <bf/record-begin/ command
-introduces the profile, and should always be called first thing when
-introducing a new record.
-
-The file may contain the following directives:
-
-<descrip>
-<tag>name <it/symbolic-name/</tag> (m) This provides a shorthand name or
-description for the profile. Mostly useful for diagnostic purposes.
-
-<tag>reference <it/OID-name/</tag> (m) The OID for
-the profile (name or dotted-numerical list).
-
-<tag>attset <it/filename/</tag> (m) The attribute set that is used for
-indexing and searching records belonging to this profile.
-
-<tag>tagset <it/filename/ [<it/type/]</tag> (o) The tag
-set (if any) that describe that fields of the records. The type, which
-is optional, specifies the tag type. If not given, the type-specifier
-in the Tag Set files is used.
-
-<tag>varset <it/filename/</tag> (o) The variant set used in the profile.
-
-<tag>maptab <it/filename/</tag> (o,r) This points to a
-conversion table that might be used if the client asks for the record
-in a different schema from the native one.
-
-<tag>marc <it/filename/</tag> (o) Points to a file containing parameters
-for representing the record contents in the ISO2709 syntax. Read the
-description of the MARC representation facility below.
-
-<tag>esetname <it/name filename/</tag> (o,r) Associates the
-given element set name with an element selection file. If an (@) is
-given in place of the filename, this corresponds to a null mapping for
-the given element set name.
-
-<tag>any <it/tags/</tag> (o) This directive specifies a list of
-attributes which should be appended to the attribute list given for each
-element. The effect is to make every single element in the abstract
-syntax searchable by way of the given attributes. This directive
-provides an efficient way of supporting free-text searching across all
-elements. However, it does increase the size of the index
-significantly. The attributes can be qualified with a structure, as in
-the <bf/elm/ directive below.
-
-<tag>elm <it/path name attributes/</tag> (o,r) Adds an element
-to the abstract record syntax of the schema. The <it/path/ follows the
-syntax which is suggested by the Z39.50 document - that is, a sequence
-of tags separated by slashes (/). Each tag is given as a
-comma-separated pair of tag type and -value surrounded by parenthesis.
-The <it/name/ is the name of the element, and the <it/attributes/
-specifies which attributes to use when indexing the element in a
-comma-separated list. A ! in
-place of the attribute name is equivalent to specifying an attribute
-name identical to the element name. A - in place of the attribute name
-specifies that no indexing is to take place for the given element. The
-attributes can be qualified with <it/field types/ to specify which
-character set should govern the indexing procedure for that field. The
-same data element may be indexed into several different fields, using
-different character set definitions. See the section
-<ref id="field structure and character sets"
-name="Field Structure and Character Sets">.
-The default field type is &dquot;w&dquot; for
-<it/word/.
-</descrip>
-
-The following is an excerpt from the abstract syntax file for the GILS
-profile.
-
-<tscreen><verb>
-name gils
-reference GILS-schema
-attset gils.att
-tagset gils.tag
-varset var1.var
-
-maptab gils-usmarc.map
-
-# Element set names
-
-esetname VARIANT gils-variant.est # for WAIS-compliance
-esetname B gils-b.est
-esetname G gils-g.est
-esetname F @
-
-elm (1,10) rank -
-elm (1,12) url -
-elm (1,14) localControlNumber Local-number
-elm (1,16) dateOfLastModification Date/time-last-modified
-elm (2,1) Title w:!,p:!
-elm (4,1) controlIdentifier Identifier-standard
-elm (2,6) abstract Abstract
-elm (4,51) purpose !
-elm (4,52) originator -
-elm (4,53) accessConstraints !
-elm (4,54) useConstraints !
-elm (4,70) availability -
-elm (4,70)/(4,90) distributor -
-elm (4,70)/(4,90)/(2,7) distributorName !
-elm (4,70)/(4,90)/(2,10 distributorOrganization !
-elm (4,70)/(4,90)/(4,2) distributorStreetAddress !
-elm (4,70)/(4,90)/(4,3) distributorCity !
-</verb></tscreen>
-
-<sect2>The Attribute Set (.att) Files<label id="attset-files">
-
-<p>
-This file type describes the <bf/Use/ elements of an attribute set.
-It contains the following directives.
-
-<descrip>
-
-<tag>name <it/symbolic-name/</tag> (m) This provides a shorthand name or
-description for the attribute set. Mostly useful for diagnostic purposes.
-
-<tag>reference <it/OID-name/</tag> (m) The reference name of the OID for
-the attribute set.
-
-<tag>include <it/filename/</tag> (o,r) This directive is used to
-include another attribute set as a part of the current one. This is
-used when a new attribute set is defined as an extension to another
-set. For instance, many new attribute sets are defined as extensions
-to the <bf/bib-1/ set. This is an important feature of the retrieval
-system of Z39.50, as it ensures the highest possible level of
-interoperability, as those access points of your database which are
-derived from the external set (say, bib-1) can be used even by clients
-who are unaware of the new set.
-
-<tag>att <it/att-value att-name [local-value]/</tag> (o,r) This
-repeatable directive introduces a new attribute to the set. The
-attribute value is stored in the index (unless a <it/local-value/ is
-given, in which case this is stored). The name is used to refer to the
-attribute from the <it/abstract syntax/. </descrip>
-
-This is an excerpt from the GILS attribute set definition. Notice how
-the file describing the <it/bib-1/ attribute set is referenced.
-
-<tscreen><verb>
-name gils
-reference GILS-attset
-include bib1.att
-
-att 2001 distributorName
-att 2002 indexTermsControlled
-att 2003 purpose
-att 2004 accessConstraints
-att 2005 useConstraints
-</verb></tscreen>
-
-<sect2>The Tag Set (.tag) Files
-
-<p>
-This file type defines the tagset of the profile, possibly by
-referencing other tag sets (most tag sets, for instance, will include
-tagsetG and tagsetM from the Z39.50 specification. The file may
-contain the following directives.
-
-<descrip>
-<tag>name <it/symbolic-name/</tag> (m) This provides a shorthand name or
-description for the tag set. Mostly useful for diagnostic purposes.
-
-<tag>reference <it/OID-name/</tag> (o) The reference name of the OID for
-the tag set. The directive is optional, since not all tag sets are
-registered outside of their schema.
-
-<tag>type <it/integer/</tag> (m) The type number of the tagset within the schema
-profile (note: this specification really should belong to the .abs
-file. This will be fixed in a future release).
-
-<tag>include <it/filename/</tag> (o,r) This directive is used
-to include the definitions of other tag sets into the current one.
-
-<tag>tag <it/number names type/</tag> (o,r) Introduces a new
-tag to the set. The <it/number/ is the tag number as used in the protocol
-(there is currently no mechanism for specifying string tags at this
-point, but this would be quick work to add). The <it/names/ parameter
-is a list of names by which the tag should be recognized in the input
-file format. The names should be separated by slashes (/). The
-<it/type/ is th recommended datatype of the tag. It should be one of
-the following:
-<itemize>
-<item>structured
-<item>string
-<item>numeric
-<item>bool
-<item>oid
-<item>generalizedtime
-<item>intunit
-<item>int
-<item>octetstring
-<item>null
-</itemize>
-</descrip>
-
-The following is an excerpt from the TagsetG definition file.
-
-<tscreen><verb>
-name tagsetg
-reference TagsetG
-type 2
-
-tag 1 title string
-tag 2 author string
-tag 3 publicationPlace string
-tag 4 publicationDate string
-tag 5 documentId string
-tag 6 abstract string
-tag 7 name string
-tag 8 date generalizedtime
-tag 9 bodyOfDisplay string
-tag 10 organization string
-</verb></tscreen>
-
-<sect2>The Variant Set (.var) Files<label id="variant-set">
-
-<p>
-The variant set file is a straightforward representation of the
-variant set definitions associated with the protocol. At present, only
-the <it/Variant-1/ set is known.
-
-These are the directives allowed in the file.
-
-<descrip>
-<tag>name <it/symbolic-name/</tag> (m) This provides a shorthand name or
-description for the variant set. Mostly useful for diagnostic purposes.
-
-<tag>reference <it/OID-name/</tag> (o) The reference name of the OID for
-the variant set, if one is required.
-
-<tag>class <it/integer class-name/</tag> (m,r) Introduces a new
-class to the variant set.
-
-<tag>type <it/integer type-name datatype/</tag> (m,r) Addes a
-new type to the current class (the one introduced by the most recent
-<bf/class/ directive). The type names belong to the same name space as
-the one used in the tag set definition file.
-</descrip>
-
-The following is an excerpt from the file describing the variant set
-<it/Variant-1/.
-
-<tscreen><verb>
-name variant-1
-reference Variant-1
-
-class 1 variantId
-
- type 1 variantId octetstring
-
-class 2 body
-
- type 1 iana string
- type 2 z39.50 string
- type 3 other string
-</verb></tscreen>
-
-<sect2>The Element Set (.est) Files
-
-<p>
-The element set specification files describe a selection of a subset
-of the elements of a database record. The element selection mechanism
-is equivalent to the one supplied by the <it/Espec-1/ syntax of the
-Z39.50 specification. In fact, the internal representation of an
-element set specification is identical to the <it/Espec-1/ structure,
-and we'll refer you to the description of that structure for most of
-the detailed semantics of the directives below.
-
-<it>
-NOTE: Not all of the Espec-1 functionality has been implemented yet.
-The fields that are mentioned below all work as expected, unless
-otherwise is noted.
-</it>
-
-The directives available in the element set file are as follows:
-
-<descrip>
-<tag>defaultVariantSetId <it/OID-name/</tag> (o) If variants are used in
-the following, this should provide the name of the variantset used
-(it's not currently possible to specify a different set in the
-individual variant request). In almost all cases (certainly all
-profiles known to us), the name <tt/Variant-1/ should be given here.
-
-<tag>defaultVariantRequest <it/variant-request/</tag> (o) This directive
-provides a default variant request for
-use when the individual element requests (see below) do not contain a
-variant request. Variant requests consist of a blank-separated list of
-variant components. A variant compont is a comma-separated,
-parenthesized triple of variant class, type, and value (the two former
-values being represented as integers). The value can currently only be
-entered as a string (this will change to depend on the definition of
-the variant in question). The special value (@) is interpreted as a
-null value, however.
-
-<tag>simpleElement <it/path ['variant' variant-request]/</tag>
-(o,r) This corresponds to a simple element request in <it/Espec-1/. The
-path consists of a sequence of tag-selectors, where each of these can
-consist of either:
-
-<itemize>
-<item>A simple tag, consisting of a comma-separated type-value pair in
-parenthesis, possibly followed by a colon (:) followed by an
-occurrences-specification (see below). The tag-value can be a number
-or a string. If the first character is an apostrophe ('), this forces
-the value to be interpreted as a string, even if it appears to be numerical.
-
-<item>A WildThing, represented as a question mark (?), possibly
-followed by a colon (:) followed by an occurrences specification (see
-below).
-
-<item>A WildPath, represented as an asterisk (*). Note that the last
-element of the path should not be a wildPath (wildpaths don't work in
-this version).
-</itemize>
-
-The occurrences-specification can be either the string <tt/all/, the
-string <tt/last/, or an explicit value-range. The value-range is
-represented as an integer (the starting point), possibly followed by a
-plus (+) and a second integer (the number of elements, default being
-one).
-
-The variant-request has the same syntax as the defaultVariantRequest
-above. Note that it may sometimes be useful to give an empty variant
-request, simply to disable the default for a specific set of fields
-(we aren't certain if this is proper <it/Espec-1/, but it works in
-this implementation).
-</descrip>
-
-The following is an example of an element specification belonging to
-the GILS profile.
-
-<tscreen><verb>
-simpleelement (1,10)
-simpleelement (1,12)
-simpleelement (2,1)
-simpleelement (1,14)
-simpleelement (4,1)
-simpleelement (4,52)
-</verb></tscreen>
-
-<sect2>The Schema Mapping (.map) Files<label id="schema-mapping">
-
-<p>
-Sometimes, the client might want to receive a database record in
-a schema that differs from the native schema of the record. For
-instance, a client might only know how to process WAIS records, while
-the database record is represented in a more specific schema, such as
-GILS. In this module, a mapping of data to one of the MARC formats is
-also thought of as a schema mapping (mapping the elements of the
-record into fields consistent with the given MARC specification, prior
-to actually converting the data to the ISO2709). This use of the
-object identifier for USMARC as a schema identifier represents an
-overloading of the OID which might not be entirely proper. However,
-it represents the dual role of schema and record syntax which
-is assumed by the MARC family in Z39.50.
-
-<it>
-NOTE: The schema-mapping functions are so far limited to a
-straightforward mapping of elements. This should be extended with
-mechanisms for conversions of the element contents, and conditional
-mappings of elements based on the record contents.
-</it>
-
-These are the directives of the schema mapping file format:
-
-<descrip>
-<tag>targetName <it/name/</tag> (m) A symbolic name for the target schema
-of the table. Useful mostly for diagnostic purposes.
-
-<tag>targetRef <it/OID-name/</tag> (m) An OID name for the target schema.
-This is used, for instance, by a server receiving a request to present
-a record in a different schema from the native one.
-
-<tag>map <it/element-name target-path/</tag> (o,r) Adds
-an element mapping rule to the table.
-</descrip>
-
-<sect2>The MARC (ISO2709) Representation (.mar) Files
-
-<p>
-This file provides rules for representing a record in the ISO2709
-format. The rules pertain mostly to the values of the constant-length
-header of the record.
-
-<it>NOTE: This will be described better. We're in the process of
-re-evaluating and most likely changing the way that MARC records are
-handled by the system.</it>
-
-<sect2>Field Structure and Character Sets
-<label id="field structure and character sets">
-
-<p>
-In order to provide a flexible approach to national character set
-handling, Zebra allows the administrator to configure the set up the
-system to handle any 8-bit character set — including sets that
-require multi-octet diacritics or other multi-octet characters. The
-definition of a character set includes a specification of the
-permissible values, their sort order (this affects the display in the
-SCAN function), and relationships between upper- and lowercase
-characters. Finally, the definition includes the specification of
-space characters for the set.
-
-The operator can define different character sets for different fields,
-typical examples being standard text fields, numerical fields, and
-special-purpose fields such as WWW-style linkages (URx).
-
-The field types, and hence character sets, are associated with data
-elements by the .abs files (see above). The file <tt/default.idx/
-provides the association between field type codes (as used in the .abs
-files) and the character map files (with the .chr suffix). The format
-of the .idx file is as follows
-
-<descrip>
-<tag>index <it/field type code/</tag>This directive introduces a new
-search index code. The argument is a one-character code to be used in the
-.abs files to select this particular index type. An index, roughly,
-corresponds to a particular structure attribute during search. Refer
-to section <ref id="search" name="Search">.
-
-<tag>sort <it/field code type/</tag>This directive introduces a
-sort index. The argument is a one-character code to be used in the
-.abs fie to select this particular index type. The corresponding
-use attribute must be used in the sort request to refer to this
-particular sort index. The corresponding character map (see below)
-is used in the sort process.
-
-<tag>completeness <it/boolean/</tag>This directive enables or disables
-complete field indexing. The value of the <it/boolean/ should be 0
-(disable) or 1. If completeness is enabled, the index entry will
-contain the complete contents of the field (up to a limit), with words
-(non-space characters) separated by single space characters
-(normalized to &dquot; &dquot; on display). When completeness is
-disabled, each word is indexed as a separate entry. Complete subfield
-indexing is most useful for fields which are typically browsed (eg.
-titles, authors, or subjects), or instances where a match on a
-complete subfield is essential (eg. exact title searching). For fields
-where completeness is disabled, the search engine will interpret a
-search containing space characters as a word proximity search.
-
-<tag>charmap <it/filename/</tag> This is the filename of the character
-map to be used for this index for field type.
-</descrip>
-
-The contents of the character map files are structured as follows:
-
-<descrip>
-<tag>lowercase <it/value-set/</tag>This directive introduces the basic
-value set of the field type. The format is an ordered list (without
-spaces) of the characters which may occur in &dquot;words&dquot; of
-the given type. The order of the entries in the list determines the
-sort order of the index. In addition to single characters, the
-following combinations are legal:
-
-<itemize>
-<item>Backslashes may be used to introduce three-digit octal, or
-two-digit hex representations of single characters (preceded by <tt/x/).
-In addition, the combinations
-\\, \\r, \\n, \\t, \\s (space — remember that real space-characters
-may ot occur in the value definition), and \\ are recognised,
-with their usual interpretation.
-
-<item>Curly braces {} may be used to enclose ranges of single
-characters (possibly using the escape convention described in the
-preceding point), eg. {a-z} to entroduce the standard range of ASCII
-characters. Note that the interpretation of such a range depends on
-the concrete representation in your local, physical character set.
-
-<item>Paranthesises () may be used to enclose multi-byte characters -
-eg. diacritics or special national combinations (eg. Spanish
-&dquot;ll&dquot;). When found in the input stream (or a search term),
-these characters are viewed and sorted as a single character, with a
-sorting value depending on the position of the group in the value
-statement.
-</itemize>
-
-<tag>uppercase <it/value-set/</tag>This directive introduces the
-upper-case equivalencis to the value set (if any). The number and
-order of the entries in the list should be the same as in the
-<tt/lowercase/ directive.
-
-<tag>space <it/value-set/</tag>This directive introduces the character
-which separate words in the input stream. Depending on the
-completeness mode of the field in question, these characters either
-terminate an index entry, or delimit individual &dquot;words&dquot; in
-the input stream. The order of the elements is not significant —
-otherwise the representation is the same as for the <tt/upercase/ and
-<tt/lowercase/ directives.
-
-<tag>map <it/value-set/ <it/target/</tag>This directive introduces a
-mapping between each of the members of the value-set on the left to
-the character on the right. The character on the right must occur in
-the value set (the <tt/lowercase/ directive) of the character set, but
-it may be a paranthesis-enclosed multi-octet character. This directive
-may be used to map diacritics to their base characters, or to map
-HTML-style character-representations to their natural form, etc.
-</descrip>
-
-<sect1>Exchange Formats
-
-<p>
-Converting records from the internal structure to en exchange format
-is largely an automatic process. Currently, the following exchange
-formats are supported:
-
-<itemize>
-<item>GRS-1. The internal representation is based on GRS-1, so the
-conversion here is straightforward. The system will create
-applied variant and supported variant lists as required, if a record
-contains variant information.
-
-<item>SUTRS. Again, the mapping is fairly straighforward. Indentation
-is used to show the hierarchical structure of the record. All
-&dquot;GRS&dquot; type records support both the GRS-1 and SUTRS
-representations.
-
-<item>ISO2709-based formats (USMARC, etc.). Only records with a
-two-level structure (corresponding to fields and subfields) can be
-directly mapped to ISO2709. For records with a different structuring
-(eg., GILS), the representation in a structure like USMARC involves a
-schema-mapping (see section <ref id="schema-mapping" name="Schema
-Mapping">), to an &dquot;implied&dquot; USMARC schema (implied,
-because there is no formal schema which specifies the use of the
-USMARC fields outside of ISO2709). The resultant, two-level record is
-then mapped directly from the internal representation to ISO2709. See
-the GILS schema definition files for a detailed example of this
-approach.
-
-<item>Explain. This representation is only available for records
-belonging to the Explain schema.
-
-<item>Summary. This ASN-1 based structure is only available for records
-belonging to the Summary schema - or schema which provide a mapping
-to this schema (see the description of the schema mapping facility
-above).
-
-<item>SOIF. Support for this syntax is experimental, and is currently
-keyed to a private Index Data OID (1.2.840.10003.5.1000.81.2). All
-abstract syntaxes can be mapped to the SOIF format, although nested
-elements are represented by concatenation of the tag names at each
-level.
-
-<item>XML. The use of XML as a transfer syntax in Z39.50 is not yet widely established
-so the use of it here must be characterised as somewhat experimental. The
-tag-names used are taken from the tag-set in use, except for local string tags
-where the tag itself is passed through unchanged.
-
-</itemize>
-
-<sect>License
-
-<p>
-Zebra
-Copyright (c) 1995-2000 Index Data ApS.
-
-All rights reserved.
-
-Use and redistribution in source or binary form, with or without
-modification, of any or all of this software and documentation is
-permitted, provided that the following Conditions 1 to 6 set out below
-are met.
-
-1. Unless prior specific written permission is obtained this copyright
-and permission notice appear with all copies of the software and its
-documentation. Notices of copyright or attribution which appear at the
-beginning of any file must remain unchanged.
-
-2. The names of Index Data or the individual authors may not be used
-to endorse or promote products derived from this software without
-specific prior written permission.
-
-3. Source code or binary versions of this software and its documentation
-may be used freely in not for profit applications limited to databases
-of 100,000 records maximum. Other applications - such as publishing over
-100,000 records, providing for-pay services, distributing a product based
-in whole or in part on this software or its documentation, or generally
-distributing this software or its documentation under a different license
-require a commercial license from Index Data.
-
-4. The software may be installed and used for evaluation purposes in
-conjunction with such commercially licensed applications for a trial
-period no longer than 60 days.
-
-5. Unless a prior specific written agreement is obtained THIS SOFTWARE
-IS PROVIDED "AS IS" AND WITHOUT WARRANTY OF ANY KIND, EXPRESS, IMPLIED,
-OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY WARRANTY OF
-MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL
-INDEX DATA BE LIABLE FOR ANY SPECIAL, INCIDENTAL, INDIRECT OR
-CONSEQUENTIAL DAMAGES OF ANY KIND, OR ANY DAMAGES WHATSOEVER RESULTING
-FROM LOSS OF USE, DATA OR PROFITS, WHETHER OR NOT ADVISED OF THE
-POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF LIABILITY, ARISING OUT OF
-OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
-
-6. Commercial licenses and support agreements for Zebra and related
-Index Data products such as Z'bol (c) - and written agreements
-relating to these Conditions may be obtained only from Index Data
-or its appointed agents as follows:
-
-Index Data: www.indexdata.dk
-Fretwell-Downing Informatics: www.fdgroup.co.uk
-Fretwell-Downing Informatics USA: www.fdi.com
-
-<sect>About Index Data and the Zebra Server
-
-<p>
-Index Data is a consulting and software-development enterprise that
-specialises in information management and retrieval applications. Our
-interests and expertise span a broad range of related fields, and one
-of our primary, long-term objectives is the development of a powerful
-information management
-system with open network interfaces and hypermedia capabilities. Zebra is an
-important component in this strategy.
-
-We make this software available free of charge for not-for-profit
-purposes, as a service to the networking community, and to further
-the development and use of quality software for open network
-communication. We encourage your comments and questions if you have ideas, things
-you would like to see in future versions, or things you would like to
-contribute.
-
-If you like this software, and would like to use all or part of it in
-a commercial product, or to provide a commercial database service,
-please contact us. The Z'mbol Information System represents the commercial
-variant of Zebra. It includes full support; additional functionality and
-performance-boosting features, and it has what we think is a very exciting
-development path.
-
-<tscreen><verb>
-Index Data
-Ryesgade 3
-DK-2200 Copenhagen N
-</verb></tscreen>
-
-<p>
-<tscreen><verb>
-Phone: +45 3536 3672
-Fax : +45 3536 0449
-Email: info@indexdata.dk
-</verb></tscreen>
-
-The <it>Random House College Dictionary</it>, 1975 edition
-offers this definition of the
-word &dquot;Zebra&dquot;:
-
-<it>
-Zebra, n., any of several horselike, African mammals of the genus Equus,
-having a characteristic pattern of black or dark-brown stripes on
-a whitish background.
-</it>
-
-</article>
projects / idzebra-moved-to-github.git / commitdiff