1 <chapter id="querymodel">
2 <!-- $Id: querymodel.xml,v 1.19 2006-06-30 14:36:12 marc Exp $ -->
3 <title>Query Model</title>
5 <sect1 id="querymodel-overview">
6 <title>Query Model Overview</title>
8 <sect2 id="querymodel-query-languages">
9 <title>Query Languages</title>
12 Zebra is born as a networking Information Retrieval engine adhering
13 to the international standards
14 <ulink url="&url.z39.50;">Z39.50</ulink> and
15 <ulink url="&url.sru;">SRU</ulink>,
17 <literal>type-1 Reverse Polish Notation (RPN)</literal> query
19 Unfortunately, this model has only defined a binary
20 encoded representation, which is used as transport packaging in
21 the Z39.50 protocol layer. This representation is not human
22 readable, nor defines any convenient way to specify queries.
25 Since the <literal>type-1 (RPN)</literal>
26 query structure has no direct, useful string
27 representation, every client application needs to provide some
28 form of mapping from a local query notation or representation to it.
32 <sect3 id="querymodel-query-languages-pqf">
33 <title>Prefix Query Format (PQF)</title>
35 Index Data has defined a textual representation in the
36 <ulink url="&url.yaz.pqf;">Prefix Query Format</ulink>, short
37 <emphasis>PQF</emphasis>, which maps
38 one-to-one to binary encoded
39 <emphasis>type-1 RPN</emphasis> queries.
40 PQF has been adopted by other
41 parties developing Z39.50 software, and is often referred to as
42 <literal>Prefix Query Notation</literal>, or in short
43 <literal>PQN</literal>. See
44 <xref linkend="querymodel-pqf"/> for further explanations and
45 descriptions of Zebra's capabilities.
49 <sect3 id="querymodel-query-languages-cql">
50 <title>Common Query Language (CQL)</title>
52 The query model of the type-1 RPN,
53 expressed in PQF/PQN is natively supported.
54 On the other hand, the default SRU
55 web services <emphasis>Common Query Language</emphasis>
56 <ulink url="&url.cql;">CQL</ulink> is not natively supported.
59 Zebra can be configured to understand and map CQL to PQF. See
60 <xref linkend="querymodel-cql-to-pqf"/>.
66 <sect2 id="querymodel-operation-types">
67 <title>Operation types</title>
69 Zebra supports all of the three different
70 <literal>Z39.50/SRU</literal> operations defined in the
71 standards: <literal>explain</literal>, <literal>search</literal>,
72 and <literal>scan</literal>. A short description of the
73 functionality and purpose of each is quite in order here.
76 <sect3 id="querymodel-operation-type-explain">
77 <title>Explain Operation</title>
79 The <emphasis>syntax</emphasis> of Z39.50/SRU queries is
80 well known to any client, but the specific
81 <emphasis>semantics</emphasis> - taking into account a
82 particular servers functionalities and abilities - must be
83 discovered from case to case. Enters the
84 <literal>explain</literal> operation, which provides the means
86 <emphasis>fields</emphasis> (also called
87 <emphasis>indexes</emphasis> or <emphasis>access points</emphasis>)
88 are provided, which default parameter the server uses, which
89 retrieve document formats are defined, and which specific parts
90 of the general query model are supported.
93 The Z39.50 embeds the <literal>explain</literal> operation
95 <literal>search</literal> in the magic
96 <literal>IR-Explain-1</literal> database;
97 see <xref linkend="querymodel-exp1"/>.
100 In SRU, <literal>explain</literal> is an entirely separate
101 operation, which returns an <literal>ZeeRex
102 XML</literal> record according to the
103 structure defined by the protocol.
106 In both cases, the information gathered through
107 <literal>explain</literal> operations can be used to
108 auto-configure a client user interface to the servers
113 <sect3 id="querymodel-operation-type-search">
114 <title>Search Operation</title>
116 Search and retrieve interactions are the raison d'ĂȘtre.
117 They are used to query the remote database and
118 return search result documents. Search queries span from
119 simple free text searches to nested complex boolean queries,
120 targeting specific indexes, and possibly enhanced with many
121 query semantic specifications. Search interactions are the heart
122 and soul of Z39.50/SRU servers.
126 <sect3 id="querymodel-operation-type-scan">
127 <title>Scan Operation</title>
129 The <literal>scan</literal> operation is a helper functionality,
130 which operates on one index or access point a time.
134 the means to investigate the content of specific indexes.
135 Scanning an index returns a handful of terms actually found in
136 the indexes, and in addition the <literal>scan</literal>
137 operation returns the number of documents indexed by each term.
138 A search client can use this information to propose proper
139 spelling of search terms, to auto-fill search boxes, or to
140 display controlled vocabularies.
149 <sect1 id="querymodel-pqf">
150 <title>Prefix Query Format syntax and semantics</title>
152 The <ulink url="&url.yaz.pqf;">PQF grammar</ulink>
153 is documented in the YAZ manual, and shall not be
154 repeated here. This textual PQF representation
155 is not transmistted to Zebra during search, but it is in the
156 client mapped to the equivalent Z39.50 binary
160 <sect2 id="querymodel-pqf-tree">
161 <title>PQF tree structure</title>
163 The PQF parse tree - or the equivalent textual representation -
164 may start with one specification of the
165 <emphasis>attribute set</emphasis> used. Following is a query
167 consists of <emphasis>atomic query parts (APT)</emphasis> or
168 <emphasis>named result sets</emphasis>, eventually
169 paired by <emphasis>boolean binary operators</emphasis>, and
170 finally <emphasis>recursively combined </emphasis> into
174 <sect3 id="querymodel-attribute-sets">
175 <title>Attribute sets</title>
177 Attribute sets define the exact meaning and semantics of queries
178 issued. Zebra comes with some predefined attribute set
179 definitions, others can easily be defined and added to the
184 <table id="querymodel-attribute-sets-table"
185 frame="all" rowsep="1" colsep="1" align="center">
187 <caption>Attribute sets predefined in Zebra</caption>
191 <td>Attribute set</td>
200 <td><literal>Explain</literal></td>
201 <td><literal>exp-1</literal></td>
202 <td>Special attribute set used on the special automagic
203 <literal>IR-Explain-1</literal> database to gain information on
204 server capabilities, database names, and database
209 <td><literal>Bib1</literal></td>
210 <td><literal>bib-1</literal></td>
211 <td>Standard PQF query language attribute set which defines the
212 semantics of Z39.50 searching. In addition, all of the
213 non-use attributes (type 2-9) define the hard-wired
219 <td><literal>GILS</literal></td>
220 <td><literal>gils</literal></td>
221 <td>Extension to the <literal>Bib1</literal> attribute set.</td>
226 <td><literal>IDXPATH</literal></td>
227 <td><literal>idxpath</literal></td>
228 <td>Hardwired XPATH like attribute set, only available for
229 indexing with the GRS record model</td>
238 The <literal>use attributes (type 1)</literal> mappings the
239 predefined attribute sets are found in the
240 attribute set configuration files <filename>tab/*.att</filename>.
244 The Zebra internal query processing is modeled after
245 the <literal>Bib1</literal> attribute set, and the non-use
246 attributes type 2-6 are hard-wired in. It is therefore essential
247 to be familiar with <xref linkend="querymodel-bib1-nonuse"/>.
251 <sect3 id="querymodel-boolean-operators">
252 <title>Boolean operators</title>
254 A pair of sub query trees, or of atomic queries, is combined
255 using the standard boolean operators into new query trees.
256 Thus, boolean operators are always internal nodes in the query tree.
259 <table id="querymodel-boolean-operators-table"
260 frame="all" rowsep="1" colsep="1" align="center">
262 <caption>Boolean operators</caption>
271 <tr><td><literal>@and</literal></td>
272 <td>binary <literal>AND</literal> operator</td>
273 <td>Set intersection of two atomic queries hit sets</td>
275 <tr><td><literal>@or</literal></td>
276 <td>binary <literal>OR</literal> operator</td>
277 <td>Set union of two atomic queries hit sets</td>
279 <tr><td><literal>@not</literal></td>
280 <td>binary <literal>AND NOT</literal> operator</td>
281 <td>Set complement of two atomic queries hit sets</td>
283 <tr><td><literal>@prox</literal></td>
284 <td>binary <literal>PROXIMITY</literal> operator</td>
285 <td>Set intersection of two atomic queries hit sets. In
286 addition, the intersection set is purged for all
287 documents which do not satisfy the requested query
288 term proximity. Usually a proper subset of the AND
295 For example, we can combine the terms
296 <emphasis>information</emphasis> and <emphasis>retrieval</emphasis>
297 into different searches in the default index of the default
298 attribute set as follows.
299 Querying for the union of all documents containing the
300 terms <emphasis>information</emphasis> OR
301 <emphasis>retrieval</emphasis>:
303 Z> find @or information retrieval
307 Querying for the intersection of all documents containing the
308 terms <emphasis>information</emphasis> AND
309 <emphasis>retrieval</emphasis>:
310 The hit set is a subset of the corresponding
313 Z> find @and information retrieval
317 Querying for the intersection of all documents containing the
318 terms <emphasis>information</emphasis> AND
319 <emphasis>retrieval</emphasis>, taking proximity into account:
320 The hit set is a subset of the corresponding
322 (see the <ulink url="&url.yaz.pqf;">PQF grammar</ulink> for
323 details on the proximity operator):
325 Z> find @prox 0 3 0 2 k 2 information retrieval
329 Querying for the intersection of all documents containing the
330 terms <emphasis>information</emphasis> AND
331 <emphasis>retrieval</emphasis>, in the same order and near each
332 other as described in the term list.
333 The hit set is a subset of the corresponding
336 Z> find "information retrieval"
342 <sect3 id="querymodel-atomic-queries">
343 <title>Atomic queries (APT)</title>
345 Atomic queries are the query parts which work on one access point
346 only. These consist of <literal>an attribute list</literal>
347 followed by a <literal>single term</literal> or a
348 <literal>quoted term list</literal>, and are often called
349 <emphasis>Attributes-Plus-Terms (APT)</emphasis> queries.
352 Atomic (APT) queries are always leaf nodes in the PQF query tree.
353 UN-supplied non-use attributes type 2-9 are either inherited from
354 higher nodes in the query tree, or are set to Zebra's default values.
355 See <xref linkend="querymodel-bib1"/> for details.
358 <table id="querymodel-atomic-queries-table"
359 frame="all" rowsep="1" colsep="1" align="center">
361 <caption>Atomic queries (APT)</caption>
371 <td><emphasis>attribute list</emphasis></td>
372 <td>List of <literal>orthogonal</literal> attributes</td>
373 <td>Any of the orthogonal attribute types may be omitted,
374 these are inherited from higher query tree nodes, or if not
375 inherited, are set to the default Zebra configuration values.
379 <td><emphasis>term</emphasis></td>
380 <td>single <literal>term</literal>
381 or <literal>quoted term list</literal> </td>
382 <td>Here the search terms or list of search terms is added
388 Querying for the term <emphasis>information</emphasis> in the
389 default index using the default attribute set, the server choice
390 of access point/index, and the default non-use attributes.
396 Equivalent query fully specified including all default values:
398 Z> find @attrset bib-1 @attr 1=1017 @attr 2=3 @attr 3=3 @attr 4=1 @attr 5=100 @attr 6=1 information
403 Finding all documents which have the term
404 <emphasis>debussy</emphasis> in the title field.
406 Z> find @attr 1=4 debussy
411 The <literal>scan</literal> operation is only supported with
412 atomic APT queries, as it is bound to one access point at a
413 time. Boolean query trees are not allowed during
414 <literal>scan</literal>.
418 For example, we might want to scan the title index, starting with
420 <emphasis>debussy</emphasis>, and displaying this and the
421 following terms in lexicographic order:
423 Z> scan @attr 1=4 debussy
429 <sect3 id="querymodel-resultset">
430 <title>Named Result Sets</title>
432 Named result sets are supported in Zebra, and result sets can be
433 used as operands without limitations. It follows that named
434 result sets are leaf nodes in the PQF query tree, exactly as
435 atomic APT queries are.
438 After the execution of a search, the result set is available at
439 the server, such that the client can use it for subsequent
440 searches or retrieval requests. The Z30.50 standard actually
441 stresses the fact that result sets are volatile. It may cease
442 to exist at any time point after search, and the server will
443 send a diagnostic to the effect that the requested
444 result set does not exist any more.
448 Defining a named result set and re-using it in the next query,
449 using <literal>yaz-client</literal>. Notice that the client, not
450 the server, assigns the string <literal>'1'</literal> to the
453 Z> f @attr 1=4 mozart
455 Number of hits: 43, setno 1
457 Z> f @and @set 1 @attr 1=4 amadeus
459 Number of hits: 14, setno 2
464 Named result sets are only supported by the Z39.50 protocol.
465 The SRU web service is stateless, and therefore the notion of
466 named result sets does not exist when accessing a Zebra server by
472 <sect3 id="querymodel-use-string">
473 <title>Zebra's special access point of type 'string'</title>
475 The numeric <literal>use (type 1)</literal> attribute is usually
476 referred to from a given
477 attribute set. In addition, Zebra let you use
478 <emphasis>any internal index
479 name defined in your configuration</emphasis>
480 as use attribute value. This is a great feature for
481 debugging, and when you do
482 not need the complexity of defined use attribute values. It is
483 the preferred way of accessing Zebra indexes directly.
486 Finding all documents which have the term list "information
487 retrieval" in an Zebra index, using it's internal full string
488 name. Scanning the same index.
490 Z> find @attr 1=sometext "information retrieval"
491 Z> scan @attr 1=sometext aterm
495 Searching or scanning
496 the bib-1 use attribute 54 using it's string name:
498 Z> find @attr 1=Code-language eng
499 Z> scan @attr 1=Code-language ""
503 It is possible to search
504 in any silly string index - if it's defined in your
505 indexation rules and can be parsed by the PQF parser.
506 This is definitely not the recommended use of
507 this facility, as it might confuse your users with some very
510 Z> find @attr 1=silly/xpath/alike[@index]/name "information retrieval"
514 See also <xref linkend="querymodel-pqf-apt-mapping"/> for details, and
515 <xref linkend="server-sru"/>
516 for the SRU PQF query extension using string names as a fast
521 <sect3 id="querymodel-use-xpath">
522 <title>Zebra's special access point of type 'XPath'
523 for GRS filters</title>
525 As we have seen above, it is possible (albeit seldom a great
527 <ulink url="http://www.w3.org/TR/xpath">XPath 1.0</ulink> based
528 search by defining <literal>use (type 1)</literal>
529 <emphasis>string</emphasis> attributes which in appearance
530 <emphasis>resemble XPath queries</emphasis>. There are two
531 problems with this approach: first, the XPath-look-alike has to
532 be defined at indexation time, no new undefined
533 XPath queries can entered at search time, and second, it might
534 confuse users very much that an XPath-alike index name in fact
535 gets populated from a possible entirely different XML element
536 than it pretends to access.
539 When using the <literal>GRS Record Model</literal>
540 (see <xref linkend="record-model-grs"/>), we have the
541 possibility to embed <emphasis>life</emphasis>
543 in the PQF queries, which are here called
544 <literal>use (type 1)</literal> <emphasis>xpath</emphasis>
545 attributes. You must enable the
546 <literal>xpath enable</literal> directive in your
547 <literal>.abs</literal> configuration files.
550 Only a <emphasis>very</emphasis> restricted subset of the
551 <ulink url="http://www.w3.org/TR/xpath">XPath 1.0</ulink>
552 standard is supported as the GRS record model is simpler than
553 a full XML DOM structure. See the following examples for
557 Finding all documents which have the term "content"
558 inside a text node found in a specific XML DOM
559 <emphasis>subtree</emphasis>, whose starting element is
562 Z> find @attr 1=/root content
563 Z> find @attr 1=/root/first content
565 <emphasis>Notice that the
566 XPath must be absolute, i.e., must start with '/', and that the
567 XPath <literal>descendant-or-self</literal> axis followed by a
568 text node selection <literal>text()</literal> is implicitly
569 appended to the stated XPath.
571 It follows that the above searches are interpreted as:
573 Z> find @attr 1=/root//text() content
574 Z> find @attr 1=/root/first//text() content
579 Searching inside attribute strings is possible:
581 Z> find @attr 1=/link/@creator morten
586 Filter the addressing XPath by a predicate working on exact
588 attributes (in the XML sense) can be done: return all those docs which
589 have the term "english" contained in one of all text sub nodes of
590 the subtree defined by the XPath
591 <literal>/record/title[@lang='en']</literal>. And similar
594 Z> find @attr 1=/record/title[@lang='en'] english
595 Z> find @attr 1=/link[@creator='sisse'] sibelius
596 Z> find @attr 1=/link[@creator='sisse']/description[@xml:lang='da'] sibelius
601 Combining numeric indexes, boolean expressions,
602 and xpath based searches is possible:
604 Z> find @attr 1=/record/title @and foo bar
605 Z> find @and @attr 1=/record/title foo @attr 1=4 bar
609 Escaping PQF keywords and other non-parseable XPath constructs
610 with <literal>'{ }'</literal> to prevent syntax errors:
612 Z> find @attr {1=/root/first[@attr='danish']} content
613 Z> find @attr {1=/record/@set} oai
617 It is worth mentioning that these dynamic performed XPath
618 queries are a performance bottleneck, as no optimized
619 specialized indexes can be used. Therefore, avoid the use of
620 this facility when speed is essential, and the database content
621 size is medium to large.
628 <sect2 id="querymodel-exp1">
629 <title>Explain Attribute Set</title>
631 The Z39.50 standard defines the
632 <ulink url="&url.z39.50.explain;">Explain</ulink> attribute set
633 <literal>Exp-1</literal>, which is used to discover information
634 about a server's search semantics and functional capabilities
635 Zebra exposes a "classic"
636 Explain database by base name <literal>IR-Explain-1</literal>, which
637 is populated with system internal information.
640 The attribute-set <literal>exp-1</literal> consists of a single
641 <literal>use attribute (type 1)</literal>.
644 In addition, the non-Use
645 <literal>bib-1</literal> attributes, that is, the types
646 <literal>Relation</literal>, <literal>Position</literal>,
647 <literal>Structure</literal>, <literal>Truncation</literal>,
648 and <literal>Completeness</literal> are imported from
649 the <literal>bib-1</literal> attribute set, and may be used
650 within any explain query.
653 <sect3 id="querymodel-exp1-use">
654 <title>Use Attributes (type = 1)</title>
656 The following Explain search attributes are supported:
657 <literal>ExplainCategory</literal> (@attr 1=1),
658 <literal>DatabaseName</literal> (@attr 1=3),
659 <literal>DateAdded</literal> (@attr 1=9),
660 <literal>DateChanged</literal>(@attr 1=10).
663 A search in the use attribute <literal>ExplainCategory</literal>
664 supports only these predefined values:
665 <literal>CategoryList</literal>, <literal>TargetInfo</literal>,
666 <literal>DatabaseInfo</literal>, <literal>AttributeDetails</literal>.
669 See <filename>tab/explain.att</filename> and the
670 <ulink url="&url.z39.50;">Z39.50</ulink> standard
671 for more information.
676 <title>Explain searches with yaz-client</title>
678 Classic Explain only defines retrieval of Explain information
679 via ASN.1. Practically no Z39.50 clients supports this. Fortunately
680 they don't have to - Zebra allows retrieval of this information
682 <literal>SUTRS</literal>, <literal>XML</literal>,
683 <literal>GRS-1</literal> and <literal>ASN.1</literal> Explain.
687 List supported categories to find out which explain commands are
691 Z> find @attr exp1 1=1 categorylist
698 Get target info, that is, investigate which databases exist at
699 this server endpoint:
702 Z> find @attr exp1 1=1 targetinfo
713 List all supported databases, the number of hits
714 is the number of databases found, which most commonly are the
716 the <literal>Default</literal> and the
717 <literal>IR-Explain-1</literal> databases.
720 Z> find @attr exp1 1=1 databaseinfo
727 Get database info record for database <literal>Default</literal>.
730 Z> find @and @attr exp1 1=1 databaseinfo @attr exp1 1=3 Default
732 Identical query with explicitly specified attribute set:
735 Z> find @attrset exp1 @and @attr 1=1 databaseinfo @attr 1=3 Default
740 Get attribute details record for database
741 <literal>Default</literal>.
742 This query is very useful to study the internal Zebra indexes.
743 If records have been indexed using the <literal>alvis</literal>
744 XSLT filter, the string representation names of the known indexes can be
748 Z> find @and @attr exp1 1=1 attributedetails @attr exp1 1=3 Default
750 Identical query with explicitly specified attribute set:
753 Z> find @attrset exp1 @and @attr 1=1 attributedetails @attr 1=3 Default
760 <sect2 id="querymodel-bib1">
761 <title>Bib1 Attribute Set</title>
763 Most of the information contained in this section is an excerpt of
764 the <literal>ATTRIBUTE SET BIB-1 (Z39.50-1995)
766 found at <ulink url="&url.z39.50.attset.bib1.1995;">. The BIB-1
767 Attribute Set Semantics</ulink> from 1995, also in an updated
768 <ulink url="&url.z39.50.attset.bib1;">Bib-1
769 Attribute Set</ulink>
770 version from 2003. Index Data is not the copyright holder of this
771 information, except for the configuration details, the listing of
772 Zebra's capabilities, and the example queries.
776 <sect3 id="querymodel-bib1-use">
777 <title>Use Attributes (type 1)</title>
780 A use attribute specifies an access point for any atomic query.
781 These access points are highly dependent on the attribute set used
782 in the query, and are user configurable using the following
783 default configuration files:
784 <filename>tab/bib1.att</filename>,
785 <filename>tab/dan1.att</filename>,
786 <filename>tab/explain.att</filename>, and
787 <filename>tab/gils.att</filename>.
788 New attribute sets can be added by adding new
789 <filename>tab/*.att</filename> configuration files, which need to
790 be sourced in the main configuration <filename>zebra.cfg</filename>.
794 In addition, Zebra allows the access of
795 <emphasis>internal index names</emphasis> and <emphasis>dynamic
796 XPath</emphasis> as use attributes; see
797 <xref linkend="querymodel-use-string"/> and
798 <xref linkend="querymodel-use-xpath"/>.
802 Phrase search for <emphasis>information retrieval</emphasis> in
803 the title-register, scanning the same register afterwards:
805 Z> find @attr 1=4 "information retrieval"
806 Z> scan @attr 1=4 information
814 <sect2 id="querymodel-bib1-nonuse">
815 <title>Zebra general Bib1 Non-Use Attributes (type 2-6)</title>
817 <sect3 id="querymodel-bib1-relation">
818 <title>Relation Attributes (type 2)</title>
821 Relation attributes describe the relationship of the access
823 of the relation) to the search term as qualified by the attributes (right
824 side of the relation), e.g., Date-publication <= 1975.
827 <table id="querymodel-bib1-relation-table"
828 frame="all" rowsep="1" colsep="1" align="center">
830 <caption>Relation Attributes (type 2)</caption>
845 <td>Less than or equal</td>
855 <td>Greater or equal</td>
860 <td>Greater than</td>
885 <td>AlwaysMatches</td>
893 The relation attributes
894 <literal>1-5</literal> are supported and work exactly as
896 All ordering operations are based on a lexicographical ordering,
897 <emphasis>expect</emphasis> when the
898 <literal>structure attribute numeric (109)</literal> is used. In
899 this case, ordering is numerical. See
900 <xref linkend="querymodel-bib1-structure"/>.
902 Z> find @attr 1=Title @attr 2=1 music
904 Number of hits: 11745, setno 1
906 Z> find @attr 1=Title @attr 2=2 music
908 Number of hits: 11771, setno 2
910 Z> find @attr 1=Title @attr 2=3 music
912 Number of hits: 532, setno 3
914 Z> find @attr 1=Title @attr 2=4 music
916 Number of hits: 11463, setno 4
918 Z> find @attr 1=Title @attr 2=5 music
920 Number of hits: 11419, setno 5
925 The relation attribute
926 <literal>Relevance (102)</literal> is supported, see
927 <xref linkend="administration-ranking"/> for full information.
931 Ranked search for <emphasis>information retrieval</emphasis> in
934 Z> find @attr 1=4 @attr 2=102 "information retrieval"
939 The relation attribute
940 <literal>AlwaysMatches (103)</literal> is in the default
942 supported in conjecture with structure attribute
943 <literal>Phrase (1)</literal> (which may be omitted by
945 It can be configured to work with other structure attributes,
946 see the configuration file
947 <filename>tab/default.idx</filename> and
948 <xref linkend="querymodel-pqf-apt-mapping"/>.
951 <literal>AlwaysMatches (103)</literal> is a
952 great way to discover how many documents have been indexed in a
953 given field. The search term is ignored, but needed for correct
954 PQF syntax. An empty search term may be supplied.
956 Z> find @attr 1=Title @attr 2=103 ""
957 Z> find @attr 1=Title @attr 2=103 @attr 4=1 ""
964 <sect3 id="querymodel-bib1-position">
965 <title>Position Attributes (type 3)</title>
968 The position attribute specifies the location of the search term
969 within the field or subfield in which it appears.
972 <table id="querymodel-bib1-position-table"
973 frame="all" rowsep="1" colsep="1" align="center">
975 <caption>Position Attributes (type 3)</caption>
985 <td>First in field </td>
990 <td>First in subfield</td>
995 <td>Any position in field</td>
1003 The position attribute values <literal>first in field (1)</literal>,
1004 and <literal>first in subfield(2)</literal> are unsupported.
1005 Using them does not trigger an error, but silent defaults to
1006 <literal>any position in field (3)</literal>.
1011 <sect3 id="querymodel-bib1-structure">
1012 <title>Structure Attributes (type 4)</title>
1015 The structure attribute specifies the type of search
1016 term. This causes the search to be mapped on
1017 different Zebra internal indexes, which must have been defined
1022 The possible values of the
1023 <literal>structure attribute (type 4)</literal> can be defined
1024 using the configuration file <filename>
1025 tab/default.idx</filename>.
1026 The default configuration is summarized in this table.
1029 <table id="querymodel-bib1-structure-table"
1030 frame="all" rowsep="1" colsep="1" align="center">
1032 <caption>Structure Attributes (type 4)</caption>
1062 <td>Date (normalized)</td>
1072 <td>Date (un-normalized)</td>
1074 <td>unsupported</td>
1077 <td>Name (normalized) </td>
1079 <td>unsupported</td>
1082 <td>Name (un-normalized) </td>
1084 <td>unsupported</td>
1089 <td>unsupported</td>
1097 <td>Free-form-text</td>
1102 <td>Document-text</td>
1107 <td>Local-number</td>
1114 <td>unsupported</td>
1117 <td>Numeric string</td>
1126 The structure attribute values
1127 <literal>Word list (6)</literal>
1128 is supported, and maps to the boolean <literal>AND</literal>
1129 combination of words supplied. The word list is useful when
1130 google-like bag-of-word queries need to be translated from a GUI
1131 query language to PQF. For example, the following queries
1134 Z> find @attr 1=Title @attr 4=6 "mozart amadeus"
1135 Z> find @attr 1=Title @and mozart amadeus
1140 The structure attribute value
1141 <literal>Free-form-text (105)</literal> and
1142 <literal>Document-text (106)</literal>
1143 are supported, and map both to the boolean <literal>OR</literal>
1144 combination of words supplied. The following queries
1147 Z> find @attr 1=Body-of-text @attr 4=105 "bach salieri teleman"
1148 Z> find @attr 1=Body-of-text @attr 4=106 "bach salieri teleman"
1149 Z> find @attr 1=Body-of-text @or bach @or salieri teleman
1151 This <literal>OR</literal> list of terms is very useful in
1152 combination with relevance ranking:
1154 Z> find @attr 1=Body-of-text @attr 2=102 @attr 4=105 "bach salieri teleman"
1159 The structure attribute value
1160 <literal>Local number (107)</literal>
1161 is supported, and maps always to the Zebra internal document ID,
1162 irrespectively which use attribute is specified. The following queries
1163 have exactly the same unique record in the hit set:
1165 Z> find @attr 4=107 10
1166 Z> find @attr 1=4 @attr 4=107 10
1167 Z> find @attr 1=1010 @attr 4=107 10
1173 the GILS schema (<literal>gils.abs</literal>), the
1174 west-bounding-coordinate is indexed as type <literal>n</literal>,
1175 and is therefore searched by specifying
1176 <emphasis>structure</emphasis>=<emphasis>Numeric String</emphasis>.
1177 To match all those records with west-bounding-coordinate greater
1178 than -114 we use the following query:
1180 Z> find @attr 4=109 @attr 2=5 @attr gils 1=2038 -114
1184 The exact mapping between PQF queries and Zebra internal indexes
1185 and index types is explained in
1186 <xref linkend="querymodel-pqf-apt-mapping"/>.
1191 <sect3 id="querymodel-bib1-truncation">
1192 <title>Truncation Attributes (type = 5)</title>
1195 The truncation attribute specifies whether variations of one or
1196 more characters are allowed between search term and hit terms, or
1197 not. Using non-default truncation attributes will broaden the
1198 document hit set of a search query.
1201 <table id="querymodel-bib1-truncation-table"
1202 frame="all" rowsep="1" colsep="1" align="center">
1204 <caption>Truncation Attributes (type 5)</caption>
1214 <td>Right truncation </td>
1219 <td>Left truncation</td>
1224 <td>Left and right truncation</td>
1229 <td>Do not truncate</td>
1234 <td>Process # in search term</td>
1252 The truncation attribute values 1-3 perform the obvious way:
1254 Z> scan @attr 1=Body-of-text schnittke
1260 Z> find @attr 1=Body-of-text @attr 5=1 schnittke
1262 Number of hits: 95, setno 7
1264 Z> find @attr 1=Body-of-text @attr 5=2 schnittke
1266 Number of hits: 81, setno 6
1268 Z> find @attr 1=Body-of-text @attr 5=3 schnittke
1270 Number of hits: 95, setno 8
1275 The truncation attribute value
1276 <literal>Process # in search term (101)</literal> is a
1277 poor-man's regular expression search. It maps
1278 each <literal>#</literal> to <literal>.*</literal>, and
1279 performs then a <literal>Regexp-1 (102)</literal> regular
1280 expression search. The following two queries are equivalent:
1282 Z> find @attr 1=Body-of-text @attr 5=101 schnit#ke
1283 Z> find @attr 1=Body-of-text @attr 5=102 schnit.*ke
1285 Number of hits: 89, setno 10
1290 The truncation attribute value
1291 <literal>Regexp-1 (102)</literal> is a normal regular search,
1292 see <xref linkend="querymodel-regular"/> for details.
1294 Z> find @attr 1=Body-of-text @attr 5=102 schnit+ke
1295 Z> find @attr 1=Body-of-text @attr 5=102 schni[a-t]+ke
1300 The truncation attribute value
1301 <literal>Regexp-2 (103) </literal> is a Zebra specific extension
1302 which allows <emphasis>fuzzy</emphasis> matches. One single
1303 error in spelling of search terms is allowed, i.e., a document
1304 is hit if it includes a term which can be mapped to the used
1305 search term by one character substitution, addition, deletion or
1308 Z> find @attr 1=Body-of-text @attr 5=100 schnittke
1310 Number of hits: 81, setno 14
1312 Z> find @attr 1=Body-of-text @attr 5=103 schnittke
1314 Number of hits: 103, setno 15
1320 <sect3 id="querymodel-bib1-completeness">
1321 <title>Completeness Attributes (type = 6)</title>
1325 The <literal>Completeness Attributes (type = 6)</literal>
1326 is used to specify that a given search term or term list is either
1327 part of the terms of a given index/field
1328 (<literal>Incomplete subfield (1)</literal>), or is
1329 what literally is found in the entire field's index
1330 (<literal>Complete field (3)</literal>).
1333 <table id="querymodel-bib1-completeness-table"
1334 frame="all" rowsep="1" colsep="1" align="center">
1335 <caption>Completeness Attributes (type = 6)</caption>
1338 <td>Completeness</td>
1345 <td>Incomplete subfield</td>
1350 <td>Complete subfield</td>
1352 <td>depreciated</td>
1355 <td>Complete field</td>
1363 The <literal>Completeness Attributes (type = 6)</literal>
1364 is only partially and conditionally
1365 supported in the sense that it is ignored if the hit index is
1366 not of structure <literal>type="w"</literal> or
1367 <literal>type="p"</literal>.
1370 <literal>Incomplete subfield (1)</literal> is the default, and
1372 register <literal>type="w"</literal>, whereas
1373 <literal>Complete field (3)</literal> triggers
1374 search and scan in index <literal>type="p"</literal>.
1377 The <literal>Complete subfield (2)</literal> is a reminiscens
1378 from the happy <literal>MARC</literal>
1379 binary format days. Zebra does not support it, but maps silently
1380 to <literal>Complete field (3)</literal>.
1384 The exact mapping between PQF queries and Zebra internal indexes
1385 and index types is explained in
1386 <xref linkend="querymodel-pqf-apt-mapping"/>.
1394 <sect1 id="querymodel-zebra">
1395 <title>Advanced Zebra PQF Features</title>
1397 The Zebra internal query engine has been extended to specific needs
1398 not covered by the <literal>bib-1</literal> attribute set query
1399 model. These extensions are <emphasis>non-standard</emphasis>
1400 and <emphasis>non-portable</emphasis>: most functional extensions
1401 are modeled over the <literal>bib-1</literal> attribute set,
1402 defining type 7-9 attributes.
1403 There are also the special
1404 <literal>string</literal> type index names for the
1405 <literal>idxpath</literal> attribute set.
1408 <sect2 id="querymodel-zebra-attr-allrecords">
1409 <title>Zebra specific retrieval of all records</title>
1411 Zebra defines a hardwired <literal>string</literal> index name
1412 called <literal>_ALLRECORDS</literal>. It matches any record
1413 contained in the database, if used in conjunction with
1414 the relation attribute
1415 <literal>AlwaysMatches (103)</literal>.
1418 The <literal>_ALLRECORDS</literal> index name is used for total database
1419 export. The search term is ignored, it may be empty.
1421 Z> find @attr 1=_ALLRECORDS @attr 2=103 ""
1425 Combination with other index types can be made. For example, to
1426 find all records which are <emphasis>not</emphasis> indexed in
1427 the <literal>Title</literal> register, issue one of the two
1430 Z> find @not @attr 1=_ALLRECORDS @attr 2=103 "" @attr 1=Title @attr 2=103 ""
1431 Z> find @not @attr 1=_ALLRECORDS @attr 2=103 "" @attr 1=4 @attr 2=103 ""
1435 The special string index <literal>_ALLRECORDS</literal> is
1436 experimental, and the provided functionality and syntax may very
1437 well change in future releases of Zebra.
1442 <sect2 id="querymodel-zebra-attr-search">
1443 <title>Zebra specific Search Extensions to all Attribute Sets</title>
1445 Zebra extends the Bib1 attribute types, and these extensions are
1446 recognized regardless of attribute
1447 set used in a <literal>search</literal> operation query.
1450 <table id="querymodel-zebra-attr-search-table"
1451 frame="all" rowsep="1" colsep="1" align="center">
1453 <caption>Zebra Search Attribute Extensions</caption>
1459 <td>Zebra version</td>
1464 <td>Embedded Sort</td>
1476 <td>Rank Weight</td>
1482 <td>Approx Limit</td>
1488 <td>Term Reference</td>
1496 <sect3 id="querymodel-zebra-attr-sorting">
1497 <title>Zebra Extension Embedded Sort Attribute (type 7)</title>
1500 The embedded sort is a way to specify sort within a query - thus
1501 removing the need to send a Sort Request separately. It is both
1502 faster and does not require clients to deal with the Sort
1507 All ordering operations are based on a lexicographical ordering,
1508 <emphasis>expect</emphasis> when the
1509 <literal>structure attribute numeric (109)</literal> is used. In
1510 this case, ordering is numerical. See
1511 <xref linkend="querymodel-bib1-structure"/>.
1515 The possible values after attribute <literal>type 7</literal> are
1516 <literal>1</literal> ascending and
1517 <literal>2</literal> descending.
1518 The attributes+term (APT) node is separate from the
1519 rest and must be <literal>@or</literal>'ed.
1520 The term associated with APT is the sorting level in integers,
1521 where <literal>0</literal> means primary sort,
1522 <literal>1</literal> means secondary sort, and so forth.
1523 See also <xref linkend="administration-ranking"/>.
1526 For example, searching for water, sort by title (ascending)
1528 Z> find @or @attr 1=1016 water @attr 7=1 @attr 1=4 0
1532 Or, searching for water, sort by title ascending, then date descending
1534 Z> find @or @or @attr 1=1016 water @attr 7=1 @attr 1=4 0 @attr 7=2 @attr 1=30 1
1538 <sect3 id="querymodel-zebra-attr-estimation">
1539 <title>Zebra Extension Term Set Attribute (type 8)</title>
1542 The Term Set feature is a facility that allows a search to store
1543 hitting terms in a "pseudo" resultset; thus a search (as usual) +
1544 a scan-like facility. Requires a client that can do named result
1545 sets since the search generates two result sets. The value for
1546 attribute 8 is the name of a result set (string). The terms in
1547 the named term set are returned as SUTRS records.
1550 For example, searching for u in title, right truncated, and
1551 storing the result in term set named 'aset'
1553 Z> find @attr 5=1 @attr 1=4 @attr 8=aset u
1557 The model has one serious flaw: we don't know the size of term
1558 set. Experimental. Do not use in production code.
1561 <sect3 id="querymodel-zebra-attr-weight">
1562 <title>Zebra Extension Rank Weight Attribute (type 9)</title>
1565 Rank weight is a way to pass a value to a ranking algorithm - so
1566 that one APT has one value - while another as a different one.
1567 See also <xref linkend="administration-ranking"/>.
1570 For example, searching for utah in title with weight 30 as well
1571 as any with weight 20:
1573 Z> find @attr 2=102 @or @attr 9=30 @attr 1=4 utah @attr 9=20 utah
1577 <sect3 id="querymodel-zebra-attr-limit">
1578 <title>Zebra Extension Approximative Limit Attribute (type 9)</title>
1581 Newer Zebra versions normally estimate hit count for every APT
1582 (leaf) in the query tree. These hit counts are returned as part of
1583 the searchResult-1 facility in the binary encoded Z39.50 search
1587 By setting a limit for the APT we can make Zebra turn into
1588 approximate hit count when a certain hit count limit is
1589 reached. A value of zero means exact hit count.
1592 For example, we might be interested in exact hit count for a, but
1593 for b we allow hit count estimates for 1000 and higher.
1595 Z> find @and a @attr 9=1000 b
1599 The estimated hit count facility makes searches faster, as one
1600 only needs to process large hit lists partially.
1603 This facility clashes with rank weight, because there all
1604 documents in the hit lists need to be examined for scoring and
1606 It is an experimental
1607 extension. Do not use in production code.
1610 <sect3 id="querymodel-zebra-attr-termref">
1611 <title>Zebra Extension Term Reference Attribute (type 10)</title>
1614 Zebra supports the <literal>searchResult-1</literal> facility.
1615 If the <literal>Term Reference Attribute (type 10)</literal> is
1616 given, that specifies a subqueryId value returned as part of the
1617 search result. It is a way for a client to name an APT part of a
1627 Experimental. Do not use in production code.
1634 <sect2 id="querymodel-zebra-attr-scan">
1635 <title>Zebra specific Scan Extensions to all Attribute Sets</title>
1637 Zebra extends the Bib1 attribute types, and these extensions are
1638 recognized regardless of attribute
1639 set used in a <literal>scan</literal> operation query.
1641 <table id="querymodel-zebra-attr-scan-table"
1642 frame="all" rowsep="1" colsep="1" align="center">
1644 <caption>Zebra Scan Attribute Extensions</caption>
1650 <td>Zebra version</td>
1655 <td>Result Set Narrow</td>
1661 <td>Approximative Limit</td>
1669 <sect3 id="querymodel-zebra-attr-narrow">
1670 <title>Zebra Extension Result Set Narrow (type 8)</title>
1673 If attribute <literal>Result Set Narrow (type 8)</literal>
1674 is given for <literal>scan</literal>, the value is the name of a
1675 result set. Each hit count in <literal>scan</literal> is
1676 <literal>@and</literal>'ed with the result set given.
1679 Consider for example
1680 the case of scanning all title fields around the
1681 scanterm <emphasis>mozart</emphasis>, then refining the scan by
1682 issuing a filtering query for <emphasis>amadeus</emphasis> to
1683 restrict the scan to the result set of the query:
1685 Z> scan @attr 1=4 mozart
1688 mozartforskningen (1)
1692 Z> f @attr 1=4 amadeus
1694 Number of hits: 15, setno 2
1696 Z> scan @attr 1=4 @attr 8=2 mozart
1699 mozartforskningen (0)
1707 Experimental. Do not use in production code.
1710 <sect3 id="querymodel-zebra-attr-approx">
1711 <title>Zebra Extension Approximative Limit (type 9)</title>
1714 The <literal>Zebra Extension Approximative Limit (type
1715 9)</literal> is a way to enable approximate
1716 hit counts for <literal>scan</literal> hit counts, in the same
1717 way as for <literal>search</literal> hit counts.
1726 Experimental and buggy. Definitely not to be used in production code.
1733 <sect2 id="querymodel-idxpath">
1734 <title>Zebra special IDXPATH Attribute Set for GRS indexing</title>
1736 The attribute-set <literal>idxpath</literal> consists of a single
1737 <literal>Use (type 1)</literal> attribute. All non-use attributes
1741 This feature is enabled when defining the
1742 <literal>xpath enable</literal> option in the GRS filter
1743 <filename>*.abs</filename> configuration files. If one wants to use
1744 the special <literal>idxpath</literal> numeric attribute set, the
1745 main Zebra configuration file <filename>zebra.cfg</filename>
1746 directive <literal>attset: idxpath.att</literal> must be enabled.
1748 <warning>The <literal>idxpath</literal> is depreciated, may not be
1749 supported in future Zebra versions, and should definitely
1750 not be used in production code.
1753 <sect3 id="querymodel-idxpath-use">
1754 <title>IDXPATH Use Attributes (type = 1)</title>
1756 This attribute set allows one to search GRS filter indexed
1757 records by XPATH like structured index names.
1760 <warning>The <literal>idxpath</literal> option defines hard-coded
1761 index names, which might clash with your own index names.
1764 <table id="querymodel-idxpath-use-table"
1765 frame="all" rowsep="1" colsep="1" align="center">
1767 <caption>Zebra specific IDXPATH Use Attributes (type 1)</caption>
1772 <td>String Index</td>
1778 <td>XPATH Begin</td>
1780 <td>_XPATH_BEGIN</td>
1781 <td>depreciated</td>
1787 <td>depreciated</td>
1790 <td>XPATH CData</td>
1792 <td>_XPATH_CDATA</td>
1793 <td>depreciated</td>
1796 <td>XPATH Attribute Name</td>
1798 <td>_XPATH_ATTR_NAME</td>
1799 <td>depreciated</td>
1802 <td>XPATH Attribute CData</td>
1804 <td>_XPATH_ATTR_CDATA</td>
1805 <td>depreciated</td>
1812 See <filename>tab/idxpath.att</filename> for more information.
1815 Search for all documents starting with root element
1816 <literal>/root</literal> (either using the numeric or the string
1819 Z> find @attrset idxpath @attr 1=1 @attr 4=3 root/
1820 Z> find @attr idxpath 1=1 @attr 4=3 root/
1821 Z> find @attr 1=_XPATH_BEGIN @attr 4=3 root/
1825 Search for all documents where specific nested XPATH
1826 <literal>/c1/c2/../cn</literal> exists. Notice the very
1827 counter-intuitive <emphasis>reverse</emphasis> notation!
1829 Z> find @attrset idxpath @attr 1=1 @attr 4=3 cn/cn-1/../c1/
1830 Z> find @attr 1=_XPATH_BEGIN @attr 4=3 cn/cn-1/../c1/
1834 Search for CDATA string <emphasis>text</emphasis> in any element
1836 Z> find @attrset idxpath @attr 1=1016 text
1837 Z> find @attr 1=_XPATH_CDATA text
1841 Search for CDATA string <emphasis>anothertext</emphasis> in any
1844 Z> find @attrset idxpath @attr 1=1015 anothertext
1845 Z> find @attr 1=_XPATH_ATTR_CDATA anothertext
1849 Search for all documents with have an XML element node
1850 including an XML attribute named <emphasis>creator</emphasis>
1852 Z> find @attrset idxpath @attr 1=3 @attr 4=3 creator
1853 Z> find @attr 1=_XPATH_ATTR_NAME @attr 4=3 creator
1857 Combining usual <literal>bib-1</literal> attribute set searches
1858 with <literal>idxpath</literal> attribute set searches:
1860 Z> find @and @attr idxpath 1=1 @attr 4=3 link/ @attr 1=4 mozart
1861 Z> find @and @attr 1=_XPATH_BEGIN @attr 4=3 link/ @attr 1=_XPATH_CDATA mozart
1865 Scanning is supported on all <literal>idxpath</literal>
1866 indexes, both specified as numeric use attributes, or as string
1869 Z> scan @attrset idxpath @attr 1=1016 text
1870 Z> scan @attr 1=_XPATH_ATTR_CDATA anothertext
1871 Z> scan @attrset idxpath @attr 1=3 @attr 4=3 ''
1879 <sect2 id="querymodel-pqf-apt-mapping">
1880 <title>Mapping from PQF atomic APT queries to Zebra internal
1881 register indexes</title>
1883 The rules for PQF APT mapping are rather tricky to grasp in the
1884 first place. We deal first with the rules for deciding which
1885 internal register or string index to use, according to the use
1886 attribute or access point specified in the query. Thereafter we
1887 deal with the rules for determining the correct structure type of
1891 <sect3 id="querymodel-pqf-apt-mapping-accesspoint">
1892 <title>Mapping of PQF APT access points</title>
1894 Zebra understands four fundamental different types of access
1895 points, of which only the
1896 <emphasis>numeric use attribute</emphasis> type access points
1897 are defined by the <ulink url="&url.z39.50;">Z39.50</ulink>
1899 All other access point types are Zebra specific, and non-portable.
1902 <table id="querymodel-zebra-mapping-accesspoint-types"
1903 frame="all" rowsep="1" colsep="1" align="center">
1905 <caption>Access point name mapping</caption>
1908 <td>Access Point</td>
1916 <td>Use attribute</td>
1918 <td>[1-9][1-9]*</td>
1919 <td>directly mapped to string index name</td>
1922 <td>String index name</td>
1924 <td>[a-zA-Z](\-?[a-zA-Z0-9])*</td>
1925 <td>normalized name is used as internal string index name</td>
1928 <td>Zebra internal index name</td>
1930 <td>_[a-zA-Z](_?[a-zA-Z0-9])*</td>
1931 <td>hardwired internal string index name</td>
1934 <td>XPATH special index</td>
1937 <td>special xpath search for GRS indexed records</td>
1943 <literal>Attribute set names</literal> and
1944 <literal>string index names</literal> are normalizes
1945 according to the following rules: all <emphasis>single</emphasis>
1946 hyphens <literal>'-'</literal> are stripped, and all upper case
1947 letters are folded to lower case.
1951 <emphasis>Numeric use attributes</emphasis> are mapped
1952 to the Zebra internal
1953 string index according to the attribute set definition in use.
1954 The default attribute set is <literal>Bib-1</literal>, and may be
1955 omitted in the PQF query.
1959 According to normalization and numeric
1960 use attribute mapping, it follows that the following
1961 PQF queries are considered equivalent (assuming the default
1962 configuration has not been altered):
1964 Z> find @attr 1=Body-of-text serenade
1965 Z> find @attr 1=bodyoftext serenade
1966 Z> find @attr 1=BodyOfText serenade
1967 Z> find @attr 1=bO-d-Y-of-tE-x-t serenade
1968 Z> find @attr 1=1010 serenade
1969 Z> find @attrset Bib-1 @attr 1=1010 serenade
1970 Z> find @attrset bib1 @attr 1=1010 serenade
1971 Z> find @attrset Bib1 @attr 1=1010 serenade
1972 Z> find @attrset b-I-b-1 @attr 1=1010 serenade
1977 The <emphasis>numerical</emphasis>
1978 <literal>use attributes (type 1)</literal>
1979 are interpreted according to the
1980 attribute sets which have been loaded in the
1981 <literal>zebra.cfg</literal> file, and are matched against specific
1982 fields as specified in the <literal>.abs</literal> file which
1983 describes the profile of the records which have been loaded.
1984 If no use attribute is provided, a default of
1985 <literal>Bib-1 Use Any (1016)</literal> is
1987 The predefined <literal>use attribute sets</literal>
1988 can be reconfigured by tweaking the configuration files
1989 <filename>tab/*.att</filename>, and
1990 new attribute sets can be defined by adding similar files in the
1991 configuration path <literal>profilePath</literal> of the server.
1995 <literal>String indexes</literal> can be accessed directly,
1996 independently which attribute set is in use. These are just
1997 ignored. The above mentioned name normalization applies.
1998 <literal>String index names</literal> are defined in the
1999 used indexing filter configuration files, for example in the
2000 <literal>GRS</literal>
2001 <filename>*.abs</filename> configuration files, or in the
2002 <literal>alvis</literal> filter XSLT indexing stylesheets.
2006 <literal>Zebra internal indexes</literal> can be accessed directly,
2007 according to the same rules as the user defined
2008 <literal>string indexes</literal>. The only difference is that
2009 <literal>Zebra internal index names</literal> are hardwired,
2011 must start with the character <literal>'_'</literal>.
2015 Finally, <literal>XPATH</literal> access points are only
2016 available using the <literal>GRS</literal> filter for indexing.
2017 These access point names must start with the character
2018 <literal>'/'</literal>, they are <emphasis>not
2019 normalized</emphasis>, but passed unaltered to the Zebra internal
2020 XPATH engine. See <xref linkend="querymodel-use-xpath"/>.
2028 <sect3 id="querymodel-pqf-apt-mapping-structuretype">
2029 <title>Mapping of PQF APT structure and completeness to
2030 register type</title>
2032 Internally Zebra has in it's default configuration several
2033 different types of registers or indexes, whose tokenization and
2034 character normalization rules differ. This reflects the fact that
2035 searching fundamental different tokens like dates, numbers,
2036 bitfields and string based text needs different rule sets.
2039 <table id="querymodel-zebra-mapping-structure-types"
2040 frame="all" rowsep="1" colsep="1" align="center">
2042 <caption>Structure and completeness mapping to register types</caption>
2046 <td>Completeness</td>
2047 <td>Register type</td>
2054 phrase (@attr 4=1), word (@attr 4=2),
2055 word-list (@attr 4=6),
2056 free-form-text (@attr 4=105), or document-text (@attr 4=106)
2058 <td>Incomplete field (@attr 6=1)</td>
2060 <td>Traditional tokenized and character normalized word index</td>
2064 phrase (@attr 4=1), word (@attr 4=2),
2065 word-list (@attr 4=6),
2066 free-form-text (@attr 4=105), or document-text (@attr 4=106)
2068 <td>complete field' (@attr 6=3)</td>
2069 <td>Phrase ('p')</td>
2070 <td>Character normalized, but not tokenized index for phrase
2075 <td>urx (@attr 4=104)</td>
2077 <td>URX/URL ('u')</td>
2078 <td>Special index for URL web addresses</td>
2081 <td>numeric (@attr 4=109)</td>
2083 <td>Numeric ('u')</td>
2084 <td>Special index for digital numbers</td>
2087 <td>key (@attr 4=3)</td>
2089 <td>Null bitmap ('0')</td>
2090 <td>Used for non-tokenizated and non-normalized bit sequences</td>
2093 <td>year (@attr 4=4)</td>
2096 <td>Non-tokenizated and non-normalized 4 digit numbers</td>
2099 <td>date (@attr 4=5)</td>
2102 <td>Non-tokenizated and non-normalized ISO date strings</td>
2108 <td>Used with special sort attribute set (@attr 7=1, @attr 7=2)</td>
2114 <td>Internal record ID register, used whenever
2115 Relation Always Matches (@attr 2=103) is specified</td>
2120 <!-- see in util/zebramap.c -->
2123 If a <emphasis>Structure</emphasis> attribute of
2124 <emphasis>Phrase</emphasis> is used in conjunction with a
2125 <emphasis>Completeness</emphasis> attribute of
2126 <emphasis>Complete (Sub)field</emphasis>, the term is matched
2127 against the contents of the phrase (long word) register, if one
2128 exists for the given <emphasis>Use</emphasis> attribute.
2129 A phrase register is created for those fields in the
2130 GRS <filename>*.abs</filename> file that contains a
2131 <literal>p</literal>-specifier.
2133 Z> scan @attr 1=Title @attr 4=1 @attr 6=3 beethoven
2135 bayreuther festspiele (1)
2136 * beethoven bibliography database (1)
2139 Z> find @attr 1=Title @attr 4=1 @attr 6=3 "beethoven bibliography"
2141 Number of hits: 0, setno 5
2143 Z> find @attr 1=Title @attr 4=1 @attr 6=3 "beethoven bibliography database"
2145 Number of hits: 1, setno 6
2150 If <emphasis>Structure</emphasis>=<emphasis>Phrase</emphasis> is
2151 used in conjunction with <emphasis>Incomplete Field</emphasis> - the
2152 default value for <emphasis>Completeness</emphasis>, the
2153 search is directed against the normal word registers, but if the term
2154 contains multiple words, the term will only match if all of the words
2155 are found immediately adjacent, and in the given order.
2156 The word search is performed on those fields that are indexed as
2157 type <literal>w</literal> in the GRS <filename>*.abs</filename> file.
2159 Z> scan @attr 1=Title @attr 4=1 @attr 6=1 beethoven
2165 Z> find @attr 1=Title @attr 4=1 @attr 6=1 beethoven
2167 Number of hits: 18, setno 1
2169 Z> find @attr 1=Title @attr 4=1 @attr 6=1 "beethoven bibliography"
2171 Number of hits: 2, setno 2
2177 If the <emphasis>Structure</emphasis> attribute is
2178 <emphasis>Word List</emphasis>,
2179 <emphasis>Free-form Text</emphasis>, or
2180 <emphasis>Document Text</emphasis>, the term is treated as a
2181 natural-language, relevance-ranked query.
2182 This search type uses the word register, i.e. those fields
2183 that are indexed as type <literal>w</literal> in the
2184 GRS <filename>*.abs</filename> file.
2188 If the <emphasis>Structure</emphasis> attribute is
2189 <emphasis>Numeric String</emphasis> the term is treated as an integer.
2190 The search is performed on those fields that are indexed
2191 as type <literal>n</literal> in the GRS
2192 <filename>*.abs</filename> file.
2196 If the <emphasis>Structure</emphasis> attribute is
2197 <emphasis>URX</emphasis> the term is treated as a URX (URL) entity.
2198 The search is performed on those fields that are indexed as type
2199 <literal>u</literal> in the <filename>*.abs</filename> file.
2203 If the <emphasis>Structure</emphasis> attribute is
2204 <emphasis>Local Number</emphasis> the term is treated as
2205 native Zebra Record Identifier.
2209 If the <emphasis>Relation</emphasis> attribute is
2210 <emphasis>Equals</emphasis> (default), the term is matched
2211 in a normal fashion (modulo truncation and processing of
2212 individual words, if required).
2213 If <emphasis>Relation</emphasis> is <emphasis>Less Than</emphasis>,
2214 <emphasis>Less Than or Equal</emphasis>,
2215 <emphasis>Greater than</emphasis>, or <emphasis>Greater than or
2216 Equal</emphasis>, the term is assumed to be numerical, and a
2217 standard regular expression is constructed to match the given
2219 If <emphasis>Relation</emphasis> is <emphasis>Relevance</emphasis>,
2220 the standard natural-language query processor is invoked.
2224 For the <emphasis>Truncation</emphasis> attribute,
2225 <emphasis>No Truncation</emphasis> is the default.
2226 <emphasis>Left Truncation</emphasis> is not supported.
2227 <emphasis>Process # in search term</emphasis> is supported, as is
2228 <emphasis>Regxp-1</emphasis>.
2229 <emphasis>Regxp-2</emphasis> enables the fault-tolerant (fuzzy)
2230 search. As a default, a single error (deletion, insertion,
2231 replacement) is accepted when terms are matched against the register
2238 <sect2 id="querymodel-regular">
2239 <title>Zebra Regular Expressions in Truncation Attribute (type = 5)</title>
2242 Each term in a query is interpreted as a regular expression if
2243 the truncation value is either <emphasis>Regxp-1 (@attr 5=102)</emphasis>
2244 or <emphasis>Regxp-2 (@attr 5=103)</emphasis>.
2245 Both query types follow the same syntax with the operands:
2248 <table id="querymodel-regular-operands-table"
2249 frame="all" rowsep="1" colsep="1" align="center">
2251 <caption>Regular Expression Operands</caption>
2254 <tr><td>one</td><td>two</td></tr>
2259 <td><literal>x</literal></td>
2260 <td>Matches the character <literal>x</literal>.</td>
2263 <td><literal>.</literal></td>
2264 <td>Matches any character.</td>
2267 <td><literal>[ .. ]</literal></td>
2268 <td>Matches the set of characters specified;
2269 such as <literal>[abc]</literal> or <literal>[a-c]</literal>.</td>
2275 The above operands can be combined with the following operators:
2278 <table id="querymodel-regular-operators-table"
2279 frame="all" rowsep="1" colsep="1" align="center">
2280 <caption>Regular Expression Operators</caption>
2283 <tr><td>one</td><td>two</td></tr>
2288 <td><literal>x*</literal></td>
2289 <td>Matches <literal>x</literal> zero or more times.
2290 Priority: high.</td>
2293 <td><literal>x+</literal></td>
2294 <td>Matches <literal>x</literal> one or more times.
2295 Priority: high.</td>
2298 <td><literal>x?</literal></td>
2299 <td> Matches <literal>x</literal> zero or once.
2300 Priority: high.</td>
2303 <td><literal>xy</literal></td>
2304 <td> Matches <literal>x</literal>, then <literal>y</literal>.
2305 Priority: medium.</td>
2308 <td><literal>x|y</literal></td>
2309 <td> Matches either <literal>x</literal> or <literal>y</literal>.
2313 <td><literal>( )</literal></td>
2314 <td>The order of evaluation may be changed by using parentheses.</td>
2320 If the first character of the <literal>Regxp-2</literal> query
2321 is a plus character (<literal>+</literal>) it marks the
2322 beginning of a section with non-standard specifiers.
2323 The next plus character marks the end of the section.
2324 Currently Zebra only supports one specifier, the error tolerance,
2325 which consists one digit.
2326 <!-- TODO Nice thing, but what does
2327 that error tolerance digit *mean*? Maybe an example would be nice? -->
2331 Since the plus operator is normally a suffix operator the addition to
2332 the query syntax doesn't violate the syntax for standard regular
2337 For example, a phrase search with regular expressions in
2338 the title-register is performed like this:
2340 Z> find @attr 1=4 @attr 5=102 "informat.* retrieval"
2345 Combinations with other attributes are possible. For example, a
2346 ranked search with a regular expression:
2348 Z> find @attr 1=4 @attr 5=102 @attr 2=102 "informat.* retrieval"
2356 The RecordType parameter in the <literal>zebra.cfg</literal> file, or
2357 the <literal>-t</literal> option to the indexer tells Zebra how to
2358 process input records.
2359 Two basic types of processing are available - raw text and structured
2360 data. Raw text is just that, and it is selected by providing the
2361 argument <literal>text</literal> to Zebra. Structured records are
2362 all handled internally using the basic mechanisms described in the
2363 subsequent sections.
2364 Zebra can read structured records in many different formats.
2370 <sect1 id="querymodel-cql-to-pqf">
2371 <title>Server Side CQL to PQF Query Translation</title>
2374 <literal><cql2rpn>l2rpn.txt</cql2rpn></literal>
2375 YAZ Frontend Virtual
2376 Hosts option, one can configure
2377 the YAZ Frontend CQL-to-PQF
2378 converter, specifying the interpretation of various
2379 <ulink url="&url.cql;">CQL</ulink>
2380 indexes, relations, etc. in terms of Type-1 query attributes.
2381 <!-- The yaz-client config file -->
2384 For example, using server-side CQL-to-PQF conversion, one might
2385 query a zebra server like this:
2388 yaz-client localhost:9999
2390 Z> find text=(plant and soil)
2393 and - if properly configured - even static relevance ranking can
2394 be performed using CQL query syntax:
2397 Z> find text = /relevant (plant and soil)
2403 By the way, the same configuration can be used to
2404 search using client-side CQL-to-PQF conversion:
2405 (the only difference is <literal>querytype cql2rpn</literal>
2407 <literal>querytype cql</literal>, and the call specifying a local
2411 yaz-client -q local/cql2pqf.txt localhost:9999
2412 Z> querytype cql2rpn
2413 Z> find text=(plant and soil)
2419 Exhaustive information can be found in the
2420 Section "Specification of CQL to RPN mappings" in the YAZ manual.
2421 <ulink url="http://www.indexdata.dk/yaz/doc/tools.tkl#tools.cql.map">
2422 http://www.indexdata.dk/yaz/doc/tools.tkl#tools.cql.map</ulink>,
2423 and shall therefore not be repeated here.
2428 <ulink url="http://www.loc.gov/z3950/agency/zing/cql/dc-indexes.html">
2429 http://www.loc.gov/z3950/agency/zing/cql/dc-indexes.html</ulink>
2430 for the Maintenance Agency's work-in-progress mapping of Dublin Core
2431 indexes to Attribute Architecture (util, XD and BIB-2)
2441 <!-- Keep this comment at the end of the file
2446 sgml-minimize-attributes:nil
2447 sgml-always-quote-attributes:t
2450 sgml-parent-document: "zebra.xml"
2451 sgml-local-catalogs: nil
2452 sgml-namecase-general:t