<!doctype linuxdoc system>
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- $Id: zebra.sgml,v 1.27 1996-06-04 08:21:13 quinn Exp $
+ $Id: zebra.sgml,v 1.36 1998-01-19 15:26:18 quinn Exp $
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<article>
<title>Zebra Server - Administrators's Guide and Reference
-<author><htmlurl url="http://www.indexdata.dk/" name="Index Data">, <tt><htmlurl url="mailto:info@index.ping.dk" name="info@index.ping.dk"></>
-<date>$Revision: 1.27 $
+<author><htmlurl url="http://www.indexdata.dk/" name="Index Data">,
+<tt><htmlurl url="mailto:info@indexdata.dk" name="info@indexdata.dk"></>
+<date>$Revision: 1.36 $
<abstract>
The Zebra information server combines a versatile fielded/free-text
search engine with a Z39.50-1995 frontend to provide a powerful and flexible
<item>
Supports random storage formats. A system of input filters driven by
regular expressions allows you to easily process most ASCII-based
-data formats.
+data formats. SGML, ISO2709 (MARC), and raw text are also supported.
<item>
Supports boolean queries as well as relevance-ranking (free-text)
server can utilise a plug-in XTI/mOSI implementation (not included) to
provide SR services over an OSI stack, as well as Z39.50 over TCP/IP.
+<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 MSVC++ to compile the system (we use version 5.0).
+
</itemize>
</itemize>
<sect1>Future Work
<p>
-This is an alfa-release of the software, to allow you to look at
-it - try it out, and assess whether it can be of use to you. We expect
-this version to be followed by a succession of beta-releases until we
-arrive at a stable first version.
+This is a beta-release of the software, to allow you to look at
+it - try it out, and assess whether it can be of use to you.
These are some of the plans that we have for the software in the near
and far future, approximately ordered after their relative importance.
<itemize>
<item>
-*Complete the support for variants. Finalize support for the WAIS
-retrieval methodology.
+*Complete the support for variants.
<item>
*Finalize the data element <it/include/ facility to support multimedia
data elements in records.
<item>
-*Port the system to Windows NT.
-
-<item>
-Add index and data compression to save disk space.
-
-<item>
Add more sophisticated relevance ranking mechanisms. Add support for soundex
and stemming. Add relevance <it/feedback/ support.
<item>
-Add Explain support.
+Complete EXPLAIN support.
<item>
Add support for very large records by implementing segmentation and/or
Unpack the distribution archive. In some cases, you may want to edit
the top-level <tt/Makefile/, eg. to select a different C compiler, or
-to specify machine-specific libraries in the <bf/NETLIB/ variable.
+to specify machine-specific libraries in the <bf/ELIBS/ variable.
When you are done editing the <tt>Makefile</tt> type:
<tscreen><verb>
# Files that describe the attribute sets supported.
attset: bib1.att
attset: gils.att
+
+# Name of character map file.
+charMap: scan.chr
</verb></tscreen>
Now, edit the file and set <tt>profilePath</tt> to the path of the
The 48 test records are located in the sub directory <tt>records</tt>.
To index these, type:
<tscreen><verb>
-$ ../index/zebraidx -t grs update records
+$ ../index/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</tt>. The word <tt>update</tt> followed
+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
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/ (the common format for structured
+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
+public.recordType: grs.sgml
</verb></tscreen>
To set the default value of the record type to <tt/text/ write:
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.
-<tag><it>group</it>.recordId</tag>
+ 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>
Enables the <it/safe update/ facility of Zebra, and tells the system
where to place the required, temporary files. See section
<ref id="shadow-registers" name="Safe Updating - Using Shadow Registers">.
-<tag>lockPath</tag>
+<tag>lockDir</tag>
Directory in which various lock files are stored.
-<tag>tempSetPath</tag>
+<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>
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>charMap</tag>
+ Specifies the filename of a character mapping. Zebra uses the path,
+ <tt>profilePath</tt>, to locate this file.
+<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
The corresponding configuration file includes:
<tscreen><verb>
esdd.recordId: file
-esdd.recordType: grs
+esdd.recordType: grs.sgml
esdd.storeKeys: 1
</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/.filter/. If no
-<it/filter/ is provided for the GRS (General Record Structure) type,
+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">).
+<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/.
<sect2>Search
<p>
-The supported query type are 1 and 101 All operators except PROXIMITY
-are currently supported. Queries can be arbitrarily complex. Named
+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
-with no limitations. Searches may span multiple databases.
+without
+limitations. Searches may span multiple databases.
The server has full support for piggy-backed present requests (see
also the following section).
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 <bf/Any/ is assumed.
+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
replacement) is accepted when terms are matched against the register
contents.
-<sect2>Present
+Zebra interprets queries in one the following ways:
+<descrip>
+<tag>1 Phrase search</tag>
+ Each token separated by white space is truncated according to the
+ value of truncation attribute. If the completeness attribute
+ is <bf/complete subfield/ the search is directed to the separate
+complete field
+ register, if one exists for the given USE attribute. For other completeness attribute values the term is split
+ into tokens according to the white-space specification in the
+ character map. Only records in which each token exists in the order
+ specified are matched.
+<tag>2 Word search</tag>
+ The token is truncated according to the value of truncation attribute.
+ The completeness attribute is ignored.
+<tag>3 Ranked search</tag>
+ Each token separated by white space is truncated according to the value
+ of truncation attribute. The completeness attribute is ignored.
+<tag>4 Numeric relation</tag>
+ The token should consist of decimal digits. The integer is matched
+ against integers in the register according to the relation attribute.
+ The truncation - and the completenss attribute is ignored.
+<tag>5 Document identifier</tag>
+ The token consists of exactly one document identifier. The
+ truncation - and the completeness attribute is ignored.
+</descrip>
+
+For ranked searches the result sets are ranked and a score
+is associated with each record. All other result sets from the
+remaining four types are non-ranked.
+
+Combinations of the structure attribute and the relation attribute
+determine how the query is interpreted. The two following tables
+define how.
+
+<verb>
+ Structure Attribute (4)
+ none phrase(1) word(2) word list(6)
+
+ none 1 1 2 3
+ = (3) 1 1 2 3
+ < (1) 4 4 4 4
+Relation <= (2) 4 4 4 4
+Attribute >= (4) 4 4 4 4
+ (2) > (5) 4 4 4 4
+ <> (6) - - - -
+ rel (102) 3 3 3 3
+ other 1 1 2 3
+
+</verb>
+
+<verb>
+ Structure Attribute (4)
+ free-form- document- local- string
+ text text number
+ (105) (106) (107) (108)
+ none 3 3 5 1
+ = (3) 3 3 5 1
+ < (1) 4 4 5 4
+ Relation <= (2) 4 4 5 4
+ Attribute >= (4) 4 4 5 4
+ (2) > (5) 4 4 5 4
+ <> (6) - - 5 -
+ rel (102) 3 3 5 3
+ other 3 3 5 1
+
+</verb>
+
+<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>
+<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
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.
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 a flexible scripting language (Tcl). The input filter
+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
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.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>
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
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/ file.
+<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
given in place of the filename, this corresponds to a null mapping for
the given element set name.
-<tag>elm <it/path name attribute/</tag> (o,r) Adds an element
+<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/attribute/
-specifies what attribute to use when indexing the element. A ! in
+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.
+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 on character set
+processing below. The default field type is &dquot;w&dquot; for
+<it/word/.
</descrip>
<it>
elm (1,12) url -
elm (1,14) localControlNumber Local-number
elm (1,16) dateOfLastModification Date/time-last-modified
-elm (2,1) Title !
+elm (2,1) Title w:!,p:!
elm (4,1) controlIdentifier Identifier-standard
elm (2,6) abstract Abstract
elm (4,51) purpose !
module of <bf/YAZ/. 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 tag within the schema
-profile.
+<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.
re-evaluating and most likely changing the way that MARC records are
handled by the system.</it>
+<sect2>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
+index code. The argument is a one-character code to be used in the
+.abs files to select this particular index type.
+
+<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>
contains variant information.
<item>SUTRS. Again, the mapping is fairly straighforward. Indentation
-is used to show the hierarchical structure of the record.
+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
<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.
+
</itemize>
<sect>License
purpose, our consulting services and expert knowledge of the software
is available to you at favorable rates.
-<tscreen>
-Index Data&nl
-Ryesgade 3&nl
-DK-2200 København N&nl
-</tscreen>
+<tscreen><verb>
+Index Data
+Ryesgade 3
+DK-2200 København N
+</verb></tscreen>
<p>
<tscreen><verb>
projects / idzebra-moved-to-github.git / blobdiff