X-Git-Url: http://git.indexdata.com/?a=blobdiff_plain;f=doc%2Fquerymodel.xml;h=831eeff71e5e7e94013c342a9a0a897c37183af8;hb=28b7414cc9cfb8fa8956c02dcf6090c665b26f9d;hp=20e6b4b942d1d314639eb7543c83c1bf1dc48961;hpb=558bf94a5f36eb89b0ca7ac4780b641da852c36b;p=idzebra-moved-to-github.git diff --git a/doc/querymodel.xml b/doc/querymodel.xml index 20e6b4b..831eeff 100644 --- a/doc/querymodel.xml +++ b/doc/querymodel.xml @@ -1,153 +1,297 @@ - - - Query Model - + + + Query Model + - Query Model Overview + Query Model Overview + + + Query Languages + + + Zebra is born as a networking Information Retrieval engine adhering + to the international standards + Z39.50 and + SRU, + and implement the + type-1 Reverse Polish Notation (RPN) query + model defined there. + Unfortunately, this model has only defined a binary + encoded representation, which is used as transport packaging in + the Z39.50 protocol layer. This representation is not human + readable, nor defines any convenient way to specify queries. + + + Since the type-1 (RPN) + query structure has no direct, useful string + representation, every client application needs to provide some + form of mapping from a local query notation or representation to it. + + + + + Prefix Query Format (PQF) + + Index Data has defined a textual representation in the + Prefix Query Format, short + PQF, which maps + one-to-one to binary encoded + type-1 RPN queries. + PQF has been adopted by other + parties developing Z39.50 software, and is often referred to as + Prefix Query Notation, or in short + PQN. See + for further explanations and + descriptions of Zebra's capabilities. + + + + + Common Query Language (CQL) + + The query model of the type-1 RPN, + expressed in PQF/PQN is natively supported. + On the other hand, the default SRU + web services Common Query Language + CQL is not natively supported. + + + Zebra can be configured to understand and map CQL to PQF. See + . + + + + - - Zebra is born as a networking Information Retrieval engine adhering - to the international standards - Z39.50 and - SRU, - and implement the query model defined there. - Unfortunately, the Z39.50 query model has only defined a binary - encoded representation, which is used as transport packaging in - the Z39.50 protocol layer. This representation is not human - readable, nor defines any convenient way to specify queries. - - - Therefore, Index Data has defined a textual representaion in the - Prefix Query Format, short - PQF, which then has been adopted by other - parties developing Z39.50 software. It is also often referred to as - Prefix Query Notation, or in short - PQN, and is thoroughly explained in - . - + + Operation types + + Zebra supports all of the three different + Z39.50/SRU operations defined in the + standards: explain, search, + and scan. A short description of the + functionality and purpose of each is quite in order here. + - - In addition, Zebra can be configured to understand and map the - Common Query Language - (CQL) - to PQF. See an introduction on the mapping to the internal query - representation in - . - - + + Explain Operation + + The syntax of Z39.50/SRU queries is + well known to any client, but the specific + semantics - taking into account a + particular servers functionalities and abilities - must be + discovered from case to case. Enters the + explain operation, which provides the means + for learning which + fields (also called + indexes or access points) + are provided, which default parameter the server uses, which + retrieve document formats are defined, and which specific parts + of the general query model are supported. + + + The Z39.50 embeds the explain operation + by performing a + search in the magic + IR-Explain-1 database; + see . + + + In SRU, explain is an entirely separate + operation, which returns an ZeeRex + XML record according to the + structure defined by the protocol. + + + In both cases, the information gathered through + explain operations can be used to + auto-configure a client user interface to the servers + capabilities. + + + + + Search Operation + + Search and retrieve interactions are the raison d'être. + They are used to query the remote database and + return search result documents. Search queries span from + simple free text searches to nested complex boolean queries, + targeting specific indexes, and possibly enhanced with many + query semantic specifications. Search interactions are the heart + and soul of Z39.50/SRU servers. + + + + + Scan Operation + + The scan operation is a helper functionality, + which operates on one index or access point a time. + + + It provides + the means to investigate the content of specific indexes. + Scanning an index returns a handful of terms actually found in + the indexes, and in addition the scan + operation returns the number of documents indexed by each term. + A search client can use this information to propose proper + spelling of search terms, to auto-fill search boxes, or to + display controlled vocabularies. + + + + + + + - Prefix Query Format structure and syntax + Prefix Query Format syntax and semantics - The - PQF - grammer is documented in the YAZ manual, and shall not be - repeated here. - This textual PQF representation - is always during search mapped to the equivalent Zebra internal + The PQF grammar + is documented in the YAZ manual, and shall not be + repeated here. This textual PQF representation + is not transmistted to Zebra during search, but it is in the + client mapped to the equivalent Z39.50 binary query parse tree. - + PQF tree structure - - The PQF parse tree - or the equivalent textual representation - - may start with one specification of the - attribute set used. Following is a query - tree, which - consists of atomic query parts, eventually - paired by boolean binary operators, and - finally recursively combined into - complex query trees. - - - - Attribute sets + The PQF parse tree - or the equivalent textual representation - + may start with one specification of the + attribute set used. Following is a query + tree, which + consists of atomic query parts (APT) or + named result sets, eventually + paired by boolean binary operators, and + finally recursively combined into + complex query trees. + + + + Attribute sets + Attribute sets define the exact meaning and semantics of queries issued. Zebra comes with some predefined attribute set definitions, others can easily be defined and added to the configuration. - - The Zebra internal query procesing is modeled after - the Bib1 attribute set, and the non-use - attributes type 2-9 are hard-wired in. It is therefore essential - to be familiar with . - - + - - - - - - - - - - - - - - - - - - - - -
Attribute sets predefined in Zebra
exp-1Explain attribute setSpecial attribute set used on the special automagic - IR-Explain-1 database to gain information on - server capabilities, database names, and database - and semantics.
bib-1Bib1 attribute setStandard PQF query language attribute set which defines the - semantics of Z39.50 searching. In addition, all of the - non-use attributes (type 2-9) define the Zebra internal query - processing
gilsGILS attribute setExtention to the Bib1 attribute set.
- + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
Attribute sets predefined in Zebra
Attribute setShort handStatusNotes
Explainexp-1Special attribute set used on the special automagic + IR-Explain-1 database to gain information on + server capabilities, database names, and database + and semantics.predefined
Bib1bib-1Standard PQF query language attribute set which defines the + semantics of Z39.50 searching. In addition, all of the + non-use attributes (types 2-11) define the hard-wired + Zebra internal query + processing.default
GILSgilsExtension to the Bib1 attribute set.predefined
+ - - Boolean operators - A pair of subquery trees, or of atomic queries, is combined - using the standard boolean operators into new query trees. + The use attributes (type 1) mappings the + predefined attribute sets are found in the + attribute set configuration files tab/*.att. - - - - - - - - - - - - - - - - - - - - - -
Boolean operators
@andbinary AND operatorSet intersection of two atomic queries hit sets
@orbinary OR operatorSet union of two atomic queries hit sets
@notbinary AND NOT operatorSet complement of two atomic queries hit sets
@proxbinary PROXIMY operatorSet intersection of two atomic queries hit sets. In - addition, the intersection set is purged for all - documents which do not satisfy the requested query - term proximity. Usually a proper subset of the AND - operation.
+ + The Zebra internal query processing is modeled after + the Bib1 attribute set, and the non-use + attributes type 2-6 are hard-wired in. It is therefore essential + to be familiar with . + - + + + Boolean operators + + A pair of sub query trees, or of atomic queries, is combined + using the standard boolean operators into new query trees. + Thus, boolean operators are always internal nodes in the query tree. + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
Boolean operators
KeywordOperatorDescription
@andbinary AND operatorSet intersection of two atomic queries hit sets
@orbinary OR operatorSet union of two atomic queries hit sets
@notbinary AND NOT operatorSet complement of two atomic queries hit sets
@proxbinary PROXIMITY operatorSet intersection of two atomic queries hit sets. In + addition, the intersection set is purged for all + documents which do not satisfy the requested query + term proximity. Usually a proper subset of the AND + operation.
+ + For example, we can combine the terms information and retrieval into different searches in the default index of the default @@ -155,158 +299,339 @@ Querying for the union of all documents containing the terms information OR retrieval: - - @or information retrieval - - - + + Z> find @or information retrieval + + + Querying for the intersection of all documents containing the terms information AND retrieval: - The hit set is a subset of the coresponding + The hit set is a subset of the corresponding OR query. - - @and information retrieval - - - + + Z> find @and information retrieval + + + Querying for the intersection of all documents containing the terms information AND retrieval, taking proximity into account: - The hit set is a subset of the coresponding - AND query. - - @prox information retrieval - - - + The hit set is a subset of the corresponding + AND query + (see the PQF grammar for + details on the proximity operator): + + Z> find @prox 0 3 0 2 k 2 information retrieval + + + Querying for the intersection of all documents containing the terms information AND retrieval, in the same order and near each - other as described in the term list - The hit set is a subset of the coresponding - PROXIMY query. - - "information retrieval" - - - - - - - Atomic queries - - Atomic queries are the query parts which work on one acess point + other as described in the term list. + The hit set is a subset of the corresponding + PROXIMITY query. + + Z> find "information retrieval" + + + + + + + Atomic queries (APT) + + Atomic queries are the query parts which work on one access point only. These consist of an attribute list followed by a single term or a - quoted term list. - - - Unsupplied non-use attributes type 2-9 are either inherited from + quoted term list, and are often called + Attributes-Plus-Terms (APT) queries. + + + Atomic (APT) queries are always leaf nodes in the PQF query tree. + UN-supplied non-use attributes types 2-11 are either inherited from higher nodes in the query tree, or are set to Zebra's default values. See for details. - - - - - - - - - + +
Atomic queries
attribute listList of orthogonal attributesAny of the orthogonal attribute types may be omitted, + + + + + + + + + + + + + + + + + - - - - + + + + + - - -
Atomic queries (APT)
NameTypeNotes
attribute listList of orthogonal attributesAny of the orthogonal attribute types may be omitted, these are inherited from higher query tree nodes, or if not inherited, are set to the default Zebra configuration values. -
termsingle term - or quoted term list Here the search terms or list of search terms is added +
termsingle term + or quoted term list Here the search terms or list of search terms is added to the query
- +
+ Querying for the term information in the - default index using the default attribite set, the server choice + default index using the default attribute set, the server choice of access point/index, and the default non-use attributes. - - "information" - - - - Equivalent query fully specified: - @attrset bib-1 @attr 1=1017 @attr 2=3 @attr 3=3 @attr 4=1 @attr 5=100 @attr 6=1 "information" + Z> find information - + + + Equivalent query fully specified including all default values: + + Z> find @attrset bib-1 @attr 1=1017 @attr 2=3 @attr 3=3 @attr 4=1 @attr 5=100 @attr 6=1 information + + - - Finding all documents which have empty titles. Notice that the - empty term must be quoted, but is otherwise legal. + + Finding all documents which have the term + debussy in the title field. - @attr 1=4 "" + Z> find @attr 1=4 debussy - + + + + The scan operation is only supported with + atomic APT queries, as it is bound to one access point at a + time. Boolean query trees are not allowed during + scan. + + + + For example, we might want to scan the title index, starting with + the term + debussy, and displaying this and the + following terms in lexicographic order: + + Z> scan @attr 1=4 debussy + + + + + + + Named Result Sets + + Named result sets are supported in Zebra, and result sets can be + used as operands without limitations. It follows that named + result sets are leaf nodes in the PQF query tree, exactly as + atomic APT queries are. + + + After the execution of a search, the result set is available at + the server, such that the client can use it for subsequent + searches or retrieval requests. The Z30.50 standard actually + stresses the fact that result sets are volatile. It may cease + to exist at any time point after search, and the server will + send a diagnostic to the effect that the requested + result set does not exist any more. + + + + Defining a named result set and re-using it in the next query, + using yaz-client. Notice that the client, not + the server, assigns the string '1' to the + named result set. + + Z> f @attr 1=4 mozart + ... + Number of hits: 43, setno 1 + ... + Z> f @and @set 1 @attr 1=4 amadeus + ... + Number of hits: 14, setno 2 + + + + + Named result sets are only supported by the Z39.50 protocol. + The SRU web service is stateless, and therefore the notion of + named result sets does not exist when accessing a Zebra server by + the SRU protocol. + + - - Zebra's special use attribute of type 'string' + Zebra's special access point of type 'string' The numeric use (type 1) attribute is usually - refered to from a given + referred to from a given attribute set. In addition, Zebra let you use any internal index - name defined in your configuration - as use atribute value. This is a great feature for + name defined in your configuration + as use attribute value. This is a great feature for debugging, and when you do - not need the complecity of defined use attribute values. It is + not need the complexity of defined use attribute values. It is the preferred way of accessing Zebra indexes directly. Finding all documents which have the term list "information - retrieval" in an Zebra index, using it's internal full string name. + retrieval" in an Zebra index, using it's internal full string + name. Scanning the same index. - @attr 1=sometext "information retrieval" + Z> find @attr 1=sometext "information retrieval" + Z> scan @attr 1=sometext aterm - + - Searching the bib-1 use attribute 54 using it's string name: + Searching or scanning + the bib-1 use attribute 54 using it's string name: - @attr 1=Code-language eng + Z> find @attr 1=Code-language eng + Z> scan @attr 1=Code-language "" - + - Searching in any silly string index - if it's defined in your + It is possible to search + in any silly string index - if it's defined in your indexation rules and can be parsed by the PQF parser. This is definitely not the recommended use of this facility, as it might confuse your users with some very unexpected results. - @attr 1=silly/xpath/alike[@index]/name "information retrieval" + Z> find @attr 1=silly/xpath/alike[@index]/name "information retrieval" - - - See for details, and - - for the SRU PQF query extention using string names as a fast - debugging facility. - - + + + See also for details, and + + for the SRU PQF query extension using string names as a fast + debugging facility. + + + + + Zebra's special access point of type 'XPath' + for GRS filters + + As we have seen above, it is possible (albeit seldom a great + idea) to emulate + XPath 1.0 based + search by defining use (type 1) + string attributes which in appearance + resemble XPath queries. There are two + problems with this approach: first, the XPath-look-alike has to + be defined at indexation time, no new undefined + XPath queries can entered at search time, and second, it might + confuse users very much that an XPath-alike index name in fact + gets populated from a possible entirely different XML element + than it pretends to access. + + + When using the GRS Record Model + (see ), we have the + possibility to embed life + XPath expressions + in the PQF queries, which are here called + use (type 1) xpath + attributes. You must enable the + xpath enable directive in your + .abs configuration files. + + + Only a very restricted subset of the + XPath 1.0 + standard is supported as the GRS record model is simpler than + a full XML DOM structure. See the following examples for + possibilities. + + + Finding all documents which have the term "content" + inside a text node found in a specific XML DOM + subtree, whose starting element is + addressed by XPath. + + Z> find @attr 1=/root content + Z> find @attr 1=/root/first content + + Notice that the + XPath must be absolute, i.e., must start with '/', and that the + XPath descendant-or-self axis followed by a + text node selection text() is implicitly + appended to the stated XPath. + + It follows that the above searches are interpreted as: + + Z> find @attr 1=/root//text() content + Z> find @attr 1=/root/first//text() content + + + + + Searching inside attribute strings is possible: + + Z> find @attr 1=/link/@creator morten + + - + + Filter the addressing XPath by a predicate working on exact + string values in + attributes (in the XML sense) can be done: return all those docs which + have the term "english" contained in one of all text sub nodes of + the subtree defined by the XPath + /record/title[@lang='en']. And similar + predicate filtering. + + Z> find @attr 1=/record/title[@lang='en'] english + Z> find @attr 1=/link[@creator='sisse'] sibelius + Z> find @attr 1=/link[@creator='sisse']/description[@xml:lang='da'] sibelius + + + + + Combining numeric indexes, boolean expressions, + and xpath based searches is possible: + + Z> find @attr 1=/record/title @and foo bar + Z> find @and @attr 1=/record/title foo @attr 1=4 bar + + + + Escaping PQF keywords and other non-parseable XPath constructs + with '{ }' to prevent client-side PQF parsing + syntax errors: + + Z> find @attr {1=/root/first[@attr='danish']} content + Z> find @attr {1=/record/@set} oai + + + + It is worth mentioning that these dynamic performed XPath + queries are a performance bottleneck, as no optimized + specialized indexes can be used. Therefore, avoid the use of + this facility when speed is essential, and the database content + size is medium to large. + - - Explain Attribute Set + + + + + + Explain Attribute Set The Z39.50 standard defines the - Explainattribute set - exp-1, which is used to discover information + Explain attribute set + Exp-1, which is used to discover information about a server's search semantics and functional capabilities Zebra exposes a "classic" Explain database by base name IR-Explain-1, which @@ -314,9 +639,9 @@ The attribute-set exp-1 consists of a single - Use (type 1) attribute. - - + use attribute (type 1). + + In addition, the non-Use bib-1 attributes, that is, the types Relation, Position, @@ -324,57 +649,58 @@ and Completeness are imported from the bib-1 attribute set, and may be used within any explain query. - + - + Use Attributes (type = 1) - - The following Explain search atributes are supported: - ExplainCategory (@attr 1=1), - DatabaseName (@attr 1=3), - DateAdded (@attr 1=9), - DateChanged(@attr 1=10). - - - A search in the use attribute ExplainCategory - supports only these predefined values: - CategoryList, TargetInfo, - DatabaseInfo, AttributeDetails. - + + The following Explain search attributes are supported: + ExplainCategory (@attr 1=1), + DatabaseName (@attr 1=3), + DateAdded (@attr 1=9), + DateChanged(@attr 1=10). + + + A search in the use attribute ExplainCategory + supports only these predefined values: + CategoryList, TargetInfo, + DatabaseInfo, AttributeDetails. + See tab/explain.att and the + Z39.50 standard for more information. - - + + Explain searches with yaz-client - - Classic Explain only defines retrieval of Explain information - via ASN.1. Pratically no Z39.50 clients supports this. Fortunately - they don't have to - Zebra allows retrieval of this information - in other formats: - SUTRS, XML, - GRS-1 and ASN.1 Explain. - - + + Classic Explain only defines retrieval of Explain information + via ASN.1. Practically no Z39.50 clients supports this. Fortunately + they don't have to - Zebra allows retrieval of this information + in other formats: + SUTRS, XML, + GRS-1 and ASN.1 Explain. + + List supported categories to find out which explain commands are supported: Z> base IR-Explain-1 - Z> @attr exp1 1=1 categorylist + Z> find @attr exp1 1=1 categorylist Z> form sutrs Z> show 1+2 - + Get target info, that is, investigate which databases exist at this server endpoint: Z> base IR-Explain-1 - Z> @attr exp1 1=1 targetinfo + Z> find @attr exp1 1=1 targetinfo Z> form xml Z> show 1+1 Z> form grs-1 @@ -383,7 +709,7 @@ Z> show 1+1 - + List all supported databases, the number of hits is the number of databases found, which most commonly are the @@ -392,7 +718,7 @@ IR-Explain-1 databases. Z> base IR-Explain-1 - Z> f @attr exp1 1=1 databaseinfo + Z> find @attr exp1 1=1 databaseinfo Z> form sutrs Z> show 1+2 @@ -402,15 +728,15 @@ Get database info record for database Default. Z> base IR-Explain-1 - Z> @and @attr exp1 1=1 databaseinfo @attr exp1 1=3 Default + Z> find @and @attr exp1 1=1 databaseinfo @attr exp1 1=3 Default Identical query with explicitly specified attribute set: Z> base IR-Explain-1 - Z> @attrset exp1 @and @attr 1=1 databaseinfo @attr 1=3 Default + Z> find @attrset exp1 @and @attr 1=1 databaseinfo @attr 1=3 Default - + Get attribute details record for database Default. @@ -420,397 +746,1663 @@ found. Z> base IR-Explain-1 - Z> @and @attr exp1 1=1 attributedetails @attr exp1 1=3 Default + Z> find @and @attr exp1 1=1 attributedetails @attr exp1 1=3 Default Identical query with explicitly specified attribute set: Z> base IR-Explain-1 - Z> @attrset exp1 @and @attr 1=1 attributedetails @attr 1=3 Default + Z> find @attrset exp1 @and @attr 1=1 attributedetails @attr 1=3 Default - - - - - Bib1 Attribute Set - - Something about querying to be written .. - - - Most of the information contained in this section is an excerpt of - the ATTRIBUTE SET BIB-1 (Z39.50-1995) - SEMANTICS, found at The BIB-1 - Attribute Set Semantics from 1995, also in an updated - Bib-1 - Attribute Set - version from 2003. Index Data is not the copyright holder of this - information. - + + + + + Bib1 Attribute Set + + Most of the information contained in this section is an excerpt of + the ATTRIBUTE SET BIB-1 (Z39.50-1995) + SEMANTICS, + found at . The BIB-1 + Attribute Set Semantics from 1995, also in an updated + Bib-1 + Attribute Set + version from 2003. Index Data is not the copyright holder of this + information, except for the configuration details, the listing of + Zebra's capabilities, and the example queries. + - Use Attributes (type = 1) - - - - Relation Attributes (type = 2) - - - - - - Position Attributes (type = 3) - - - - Structure Attributes (type = 4) - - - - Truncation Attributes (type = 5) - + Use Attributes (type 1) - - Completeness Attributes (type = 6) - + + A use attribute specifies an access point for any atomic query. + These access points are highly dependent on the attribute set used + in the query, and are user configurable using the following + default configuration files: + tab/bib1.att, + tab/dan1.att, + tab/explain.att, and + tab/gils.att. + + + For example, some few Bib-1 use + attributes from the tab/bib1.att are: + + att 1 Personal-name + att 2 Corporate-name + att 3 Conference-name + att 4 Title + ... + att 1009 Subject-name-personal + att 1010 Body-of-text + att 1011 Date/time-added-to-db + ... + att 1016 Any + att 1017 Server-choice + att 1018 Publisher + ... + att 1035 Anywhere + att 1036 Author-Title-Subject + + + + New attribute sets can be added by adding new + tab/*.att configuration files, which need to + be sourced in the main configuration zebra.cfg. + + + In addition, Zebra allows the access of + internal index names and dynamic + XPath as use attributes; see + and + . + - - Zebra Extention Sorting Attributes (type = 7) - + + Phrase search for information retrieval in + the title-register, scanning the same register afterwards: + + Z> find @attr 1=4 "information retrieval" + Z> scan @attr 1=4 information + + + - - Zebra Extention Search Estimation Attributes (type = 8) - + - - Zebra Extention Weight Attributes (type = 9) - - - - - Mapping from Bib1 Attributes to Zebra internal - register indexes + + Zebra general Bib1 Non-Use Attributes (type 2-6) + + + Relation Attributes (type 2) + + + Relation attributes describe the relationship of the access + point (left side + of the relation) to the search term as qualified by the attributes (right + side of the relation), e.g., Date-publication <= 1975. + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
Relation Attributes (type 2)
RelationValueNotes
Less than1supported
Less than or equal2supported
Equal3default
Greater or equal4supported
Greater than5supported
Not equal6unsupported
Phonetic100unsupported
Stem101unsupported
Relevance102supported
AlwaysMatches103supported
+ + The relation attributes + 1-5 are supported and work exactly as + expected. + All ordering operations are based on a lexicographical ordering, + expect when the + structure attribute numeric (109) is used. In + this case, ordering is numerical. See + . + + Z> find @attr 1=Title @attr 2=1 music + ... + Number of hits: 11745, setno 1 + ... + Z> find @attr 1=Title @attr 2=2 music + ... + Number of hits: 11771, setno 2 + ... + Z> find @attr 1=Title @attr 2=3 music + ... + Number of hits: 532, setno 3 + ... + Z> find @attr 1=Title @attr 2=4 music + ... + Number of hits: 11463, setno 4 + ... + Z> find @attr 1=Title @attr 2=5 music + ... + Number of hits: 11419, setno 5 + - - Use attributes are interpreted according to the - attribute sets which have been loaded in the - zebra.cfg file, and are matched against specific - fields as specified in the .abs file which - describes the profile of the records which have been loaded. - If no Use attribute is provided, a default of Bib-1 Any is assumed. - + + The relation attribute + Relevance (102) is supported, see + for full information. + + + + Ranked search for information retrieval in + the title-register: + + Z> find @attr 1=4 @attr 2=102 "information retrieval" + + - - If a Structure attribute of - Phrase is used in conjunction with a - Completeness attribute of - Complete (Sub)field, the term is matched - against the contents of the phrase (long word) register, if one - exists for the given Use attribute. - A phrase register is created for those fields in the - .abs file that contains a - p-specifier. - - + + The relation attribute + AlwaysMatches (103) is in the default + configuration + supported in conjecture with structure attribute + Phrase (1) (which may be omitted by + default). + It can be configured to work with other structure attributes, + see the configuration file + tab/default.idx and + . + + + AlwaysMatches (103) is a + great way to discover how many documents have been indexed in a + given field. The search term is ignored, but needed for correct + PQF syntax. An empty search term may be supplied. + + Z> find @attr 1=Title @attr 2=103 "" + Z> find @attr 1=Title @attr 2=103 @attr 4=1 "" + + - - If Structure=Phrase is - used in conjunction with Incomplete Field - the - default value for 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 w in the .abs file. - - - If the Structure attribute is - Word List, - Free-form Text, or - 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 w in the - .abs file. - + - - If the Structure attribute is - Numeric String the term is treated as an integer. - The search is performed on those fields that are indexed - as type n in the .abs file. - + + Position Attributes (type 3) + + + The position attribute specifies the location of the search term + within the field or subfield in which it appears. + - - If the Structure attribute is - URx the term is treated as a URX (URL) entity. - The search is performed on those fields that are indexed as type - u in the .abs file. - + + + + + + + + + + + + + + + + + + + + + + + + + + + +
Position Attributes (type 3)
PositionValueNotes
First in field 1unsupported
First in subfield2unsupported
Any position in field3supported
+ + + The position attribute values first in field (1), + and first in subfield(2) are unsupported. + Using them silently maps to + any position in field (3). A proper diagnostic + should have been issued. + + + + + Structure Attributes (type 4) + + + The structure attribute specifies the type of search + term. This causes the search to be mapped on + different Zebra internal indexes, which must have been defined + at index time. + - - If the Structure attribute is - Local Number the term is treated as - native Zebra Record Identifier. - + + The possible values of the + structure attribute (type 4) can be defined + using the configuration file + tab/default.idx. + The default configuration is summarized in this table. + - - If the Relation attribute is - Equals (default), the term is matched - in a normal fashion (modulo truncation and processing of - individual words, if required). - If Relation is Less Than, - Less Than or Equal, - Greater than, or Greater than or - Equal, the term is assumed to be numerical, and a - standard regular expression is constructed to match the given - expression. - If Relation is Relevance, - the standard natural-language query processor is invoked. - + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
Structure Attributes (type 4)
StructureValueNotes
Phrase 1default
Word2supported
Key3supported
Year4supported
Date (normalized)5supported
Word list6supported
Date (un-normalized)100unsupported
Name (normalized) 101unsupported
Name (un-normalized) 102unsupported
Structure103unsupported
Urx104supported
Free-form-text105supported
Document-text106supported
Local-number107supported
String108unsupported
Numeric string109supported
+ - - For the Truncation attribute, - No Truncation is the default. - Left Truncation is not supported. - Process # in search term is supported, as is - Regxp-1. - 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. - - + + The structure attribute values + Word list (6) + is supported, and maps to the boolean AND + combination of words supplied. The word list is useful when + google-like bag-of-word queries need to be translated from a GUI + query language to PQF. For example, the following queries + are equivalent: + + Z> find @attr 1=Title @attr 4=6 "mozart amadeus" + Z> find @attr 1=Title @and mozart amadeus + + - - Regular expressions + + The structure attribute value + Free-form-text (105) and + Document-text (106) + are supported, and map both to the boolean OR + combination of words supplied. The following queries + are equivalent: + + Z> find @attr 1=Body-of-text @attr 4=105 "bach salieri teleman" + Z> find @attr 1=Body-of-text @attr 4=106 "bach salieri teleman" + Z> find @attr 1=Body-of-text @or bach @or salieri teleman + + This OR list of terms is very useful in + combination with relevance ranking: + + Z> find @attr 1=Body-of-text @attr 2=102 @attr 4=105 "bach salieri teleman" + + - Each term in a query is interpreted as a regular expression if - the truncation value is either Regxp-1 (102) - or Regxp-2 (103). - Both query types follow the same syntax with the operands: - - - - x - - - Matches the character x. - - - - - . - - - Matches any character. - - - - - [..] - - - Matches the set of characters specified; - such as [abc] or [a-c]. - - - - - and the operators: - - - - x* - - - Matches x zero or more times. Priority: high. - - - - - x+ - - - Matches x one or more times. Priority: high. - - - - - x? - - - Matches x zero or once. Priority: high. - - - - - xy - - - Matches x, then y. - Priority: medium. - - - - - x|y - - - Matches either x or y. - Priority: low. - - - - - The order of evaluation may be changed by using parentheses. - - - - If the first character of the Regxp-2 query - is a plus character (+) 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. + The structure attribute value + Local number (107) + is supported, and maps always to the Zebra internal document ID, + irrespectively which use attribute is specified. The following queries + have exactly the same unique record in the hit set: + + Z> find @attr 4=107 10 + Z> find @attr 1=4 @attr 4=107 10 + Z> find @attr 1=1010 @attr 4=107 10 + - Since the plus operator is normally a suffix operator the addition to - the query syntax doesn't violate the syntax for standard regular - expressions. + In + the GILS schema (gils.abs), the + west-bounding-coordinate is indexed as type n, + and is therefore searched by specifying + structure=Numeric String. + To match all those records with west-bounding-coordinate greater + than -114 we use the following query: + + Z> find @attr 4=109 @attr 2=5 @attr gils 1=2038 -114 + + + The exact mapping between PQF queries and Zebra internal indexes + and index types is explained in + . + + + + + Truncation Attributes (type = 5) + + + The truncation attribute specifies whether variations of one or + more characters are allowed between search term and hit terms, or + not. Using non-default truncation attributes will broaden the + document hit set of a search query. + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
Truncation Attributes (type 5)
TruncationValueNotes
Right truncation 1supported
Left truncation2supported
Left and right truncation3supported
Do not truncate100default
Process # in search term101supported
RegExpr-1 102supported
RegExpr-2103supported
+ + + The truncation attribute values 1-3 perform the obvious way: + + Z> scan @attr 1=Body-of-text schnittke + ... + * schnittke (81) + schnittkes (31) + schnittstelle (1) + ... + Z> find @attr 1=Body-of-text @attr 5=1 schnittke + ... + Number of hits: 95, setno 7 + ... + Z> find @attr 1=Body-of-text @attr 5=2 schnittke + ... + Number of hits: 81, setno 6 + ... + Z> find @attr 1=Body-of-text @attr 5=3 schnittke + ... + Number of hits: 95, setno 8 + + + + + The truncation attribute value + Process # in search term (101) is a + poor-man's regular expression search. It maps + each # to .*, and + performs then a Regexp-1 (102) regular + expression search. The following two queries are equivalent: + + Z> find @attr 1=Body-of-text @attr 5=101 schnit#ke + Z> find @attr 1=Body-of-text @attr 5=102 schnit.*ke + ... + Number of hits: 89, setno 10 + + + + + The truncation attribute value + Regexp-1 (102) is a normal regular search, + see for details. + + Z> find @attr 1=Body-of-text @attr 5=102 schnit+ke + Z> find @attr 1=Body-of-text @attr 5=102 schni[a-t]+ke + + + + + The truncation attribute value + Regexp-2 (103) is a Zebra specific extension + which allows fuzzy matches. One single + error in spelling of search terms is allowed, i.e., a document + is hit if it includes a term which can be mapped to the used + search term by one character substitution, addition, deletion or + change of position. + + Z> find @attr 1=Body-of-text @attr 5=100 schnittke + ... + Number of hits: 81, setno 14 + ... + Z> find @attr 1=Body-of-text @attr 5=103 schnittke + ... + Number of hits: 103, setno 15 + ... + + + + + + Completeness Attributes (type = 6) + + + + The Completeness Attributes (type = 6) + is used to specify that a given search term or term list is either + part of the terms of a given index/field + (Incomplete subfield (1)), or is + what literally is found in the entire field's index + (Complete field (3)). + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
Completeness Attributes (type = 6)
CompletenessValueNotes
Incomplete subfield1default
Complete subfield2deprecated
Complete field3supported
+ + + The Completeness Attributes (type = 6) + is only partially and conditionally + supported in the sense that it is ignored if the hit index is + not of structure type="w" or + type="p". + + + Incomplete subfield (1) is the default, and + makes Zebra use + register type="w", whereas + Complete field (3) triggers + search and scan in index type="p". + + + The Complete subfield (2) is a reminiscens + from the happy MARC + binary format days. Zebra does not support it, but maps silently + to Complete field (3). + + + + The exact mapping between PQF queries and Zebra internal indexes + and index types is explained in + . + + + + - - Query examples + + Advanced Zebra PQF Features + + The Zebra internal query engine has been extended to specific needs + not covered by the bib-1 attribute set query + model. These extensions are non-standard + and non-portable: most functional extensions + are modeled over the bib-1 attribute set, + defining type 7-9 attributes. + There are also the special + string type index names for the + idxpath attribute set. + + + + Zebra specific retrieval of all records - Phrase search for information retrieval in - the title-register: + Zebra defines a hardwired string index name + called _ALLRECORDS. It matches any record + contained in the database, if used in conjunction with + the relation attribute + AlwaysMatches (103). + + + The _ALLRECORDS index name is used for total database + export. The search term is ignored, it may be empty. - @attr 1=4 "information retrieval" + Z> find @attr 1=_ALLRECORDS @attr 2=103 "" + + Combination with other index types can be made. For example, to + find all records which are not indexed in + the Title register, issue one of the two + equivalent queries: + + Z> find @not @attr 1=_ALLRECORDS @attr 2=103 "" @attr 1=Title @attr 2=103 "" + Z> find @not @attr 1=_ALLRECORDS @attr 2=103 "" @attr 1=4 @attr 2=103 "" + + + + The special string index _ALLRECORDS is + experimental, and the provided functionality and syntax may very + well change in future releases of Zebra. + + + + + Zebra specific Search Extensions to all Attribute Sets - Ranked search for the same thing: + Zebra extends the Bib1 attribute types, and these extensions are + recognized regardless of attribute + set used in a search operation query. + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
Zebra Search Attribute Extensions
NameValueOperationZebra version
Embedded Sort7search1.1
Term Set8search1.1
Rank Weight9search1.1
Approx Limit9search1.4
Term Reference10search1.4
+ + + Zebra Extension Embedded Sort Attribute (type 7) + + + The embedded sort is a way to specify sort within a query - thus + removing the need to send a Sort Request separately. It is both + faster and does not require clients to deal with the Sort + Facility. + + + + All ordering operations are based on a lexicographical ordering, + expect when the + structure attribute numeric (109) is used. In + this case, ordering is numerical. See + . + + + + The possible values after attribute type 7 are + 1 ascending and + 2 descending. + The attributes+term (APT) node is separate from the + rest and must be @or'ed. + The term associated with APT is the sorting level in integers, + where 0 means primary sort, + 1 means secondary sort, and so forth. + See also . + + + For example, searching for water, sort by title (ascending) - @attr 1=4 @attr 2=102 "Information retrieval" + Z> find @or @attr 1=1016 water @attr 7=1 @attr 1=4 0 + + Or, searching for water, sort by title ascending, then date descending + + Z> find @or @or @attr 1=1016 water @attr 7=1 @attr 1=4 0 @attr 7=2 @attr 1=30 1 + + + + + + + + + + Zebra Extension Rank Weight Attribute (type 9) + - Phrase search with a regular expression: + Rank weight is a way to pass a value to a ranking algorithm - so + that one APT has one value - while another as a different one. + See also . + + + For example, searching for utah in title with weight 30 as well + as any with weight 20: + + Z> find @attr 2=102 @or @attr 9=30 @attr 1=4 utah @attr 9=20 utah + + + + + Zebra Extension Approximative Limit Attribute (type 11) + + + Zebra computes - unless otherwise configured - + the exact hit count for every APT + (leaf) in the query tree. These hit counts are returned as part of + the searchResult-1 facility in the binary encoded Z39.50 search + response packages. + + + By setting an estimation limit size of the resultset of the APT + leaves, Zebra stoppes processing the result set when the limit + length is reached. + Hit counts under this limit are still precise, but hit counts over it + are estimated using the statistics gathered from the chopped + result set. + + + Specifying a limit of 0 resuts in exact hit counts. + + + For example, we might be interested in exact hit count for a, but + for b we allow hit count estimates for 1000 and higher. - @attr 1=4 @attr 5=102 "informat.* retrieval" + Z> find @and a @attr 11=1000 b + + The estimated hit count facility makes searches faster, as one + only needs to process large hit lists partially. + It is mostly used in huge databases, where you you want trade + exactness of hit counts against speed of execution. + + + Do not use approximative hit count limits + in conjunction with relevance ranking, as re-sorting of the + result set obviosly only works when the entire result set has + been processed. + + + This facility clashes with rank weight, because there all + documents in the hit lists need to be examined for scoring and + re-sorting. + It is an experimental + extension. Do not use in production code. + + + + Zebra Extension Term Reference Attribute (type 10) + + + Zebra supports the searchResult-1 facility. + If the Term Reference Attribute (type 10) is + given, that specifies a subqueryId value returned as part of the + search result. It is a way for a client to name an APT part of a + query. + + + + Experimental. Do not use in production code. + + + + + + + Zebra specific Scan Extensions to all Attribute Sets - Ranked search with a regular expression: + Zebra extends the Bib1 attribute types, and these extensions are + recognized regardless of attribute + set used in a scan operation query. + + + + + + + + + + + + + + + + + + + + + + + + + + +
Zebra Scan Attribute Extensions
NameTypeOperationZebra version
Result Set Narrow8scan1.3
Approximative Limit9scan1.4
+ + + Zebra Extension Result Set Narrow (type 8) + + + If attribute Result Set Narrow (type 8) + is given for scan, the value is the name of a + result set. Each hit count in scan is + @and'ed with the result set given. + + + Consider for example + the case of scanning all title fields around the + scanterm mozart, then refining the scan by + issuing a filtering query for amadeus to + restrict the scan to the result set of the query: - @attr 1=4 @attr 5=102 @attr 2=102 "informat.* retrieval" + Z> scan @attr 1=4 mozart + ... + * mozart (43) + mozartforskningen (1) + mozartiana (1) + mozarts (16) + ... + Z> f @attr 1=4 amadeus + ... + Number of hits: 15, setno 2 + ... + Z> scan @attr 1=4 @attr 8=2 mozart + ... + * mozart (14) + mozartforskningen (0) + mozartiana (0) + mozarts (1) + ... + + + Experimental. Do not use in production code. + + + Zebra Extension Approximative Limit (type 11) + + + The Zebra Extension Approximative Limit (type + 11) is a way to enable approximate + hit counts for scan hit counts, in the same + way as for search hit counts. + + + + Experimental and buggy. Definitely not to be used in production code. + + + + + + + + Zebra special IDXPATH Attribute Set for GRS indexing + + The attribute-set idxpath consists of a single + Use (type 1) attribute. All non-use attributes + behave as normal. + + + This feature is enabled when defining the + xpath enable option in the GRS filter + *.abs configuration files. If one wants to use + the special idxpath numeric attribute set, the + main Zebra configuration file zebra.cfg + directive attset: idxpath.att must be enabled. + + The idxpath is deprecated, may not be + supported in future Zebra versions, and should definitely + not be used in production code. + + + + IDXPATH Use Attributes (type = 1) + + This attribute set allows one to search GRS filter indexed + records by XPATH like structured index names. + + + The idxpath option defines hard-coded + index names, which might clash with your own index names. + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
Zebra specific IDXPATH Use Attributes (type 1)
IDXPATHValueString IndexNotes
XPATH Begin1_XPATH_BEGINdeprecated
XPATH End2_XPATH_ENDdeprecated
XPATH CData1016_XPATH_CDATAdeprecated
XPATH Attribute Name3_XPATH_ATTR_NAMEdeprecated
XPATH Attribute CData1015_XPATH_ATTR_CDATAdeprecated
+ + + + See tab/idxpath.att for more information. + + + Search for all documents starting with root element + /root (either using the numeric or the string + use attributes): + + Z> find @attrset idxpath @attr 1=1 @attr 4=3 root/ + Z> find @attr idxpath 1=1 @attr 4=3 root/ + Z> find @attr 1=_XPATH_BEGIN @attr 4=3 root/ + + + + Search for all documents where specific nested XPATH + /c1/c2/../cn exists. Notice the very + counter-intuitive reverse notation! + + Z> find @attrset idxpath @attr 1=1 @attr 4=3 cn/cn-1/../c1/ + Z> find @attr 1=_XPATH_BEGIN @attr 4=3 cn/cn-1/../c1/ + + + + Search for CDATA string text in any element + + Z> find @attrset idxpath @attr 1=1016 text + Z> find @attr 1=_XPATH_CDATA text + + + + Search for CDATA string anothertext in any + attribute: + + Z> find @attrset idxpath @attr 1=1015 anothertext + Z> find @attr 1=_XPATH_ATTR_CDATA anothertext + + + + Search for all documents with have an XML element node + including an XML attribute named creator + + Z> find @attrset idxpath @attr 1=3 @attr 4=3 creator + Z> find @attr 1=_XPATH_ATTR_NAME @attr 4=3 creator + + + + Combining usual bib-1 attribute set searches + with idxpath attribute set searches: + + Z> find @and @attr idxpath 1=1 @attr 4=3 link/ @attr 1=4 mozart + Z> find @and @attr 1=_XPATH_BEGIN @attr 4=3 link/ @attr 1=_XPATH_CDATA mozart + + + + Scanning is supported on all idxpath + indexes, both specified as numeric use attributes, or as string + index names. + + Z> scan @attrset idxpath @attr 1=1016 text + Z> scan @attr 1=_XPATH_ATTR_CDATA anothertext + Z> scan @attrset idxpath @attr 1=3 @attr 4=3 '' + + + + + + + + + Mapping from PQF atomic APT queries to Zebra internal + register indexes + + The rules for PQF APT mapping are rather tricky to grasp in the + first place. We deal first with the rules for deciding which + internal register or string index to use, according to the use + attribute or access point specified in the query. Thereafter we + deal with the rules for determining the correct structure type of + the named register. + + + + Mapping of PQF APT access points + + Zebra understands four fundamental different types of access + points, of which only the + numeric use attribute type access points + are defined by the Z39.50 + standard. + All other access point types are Zebra specific, and non-portable. + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
Access point name mapping
Access PointTypeGrammarNotes
Use attributenumeric[1-9][1-9]*directly mapped to string index name
String index namestring[a-zA-Z](\-?[a-zA-Z0-9])*normalized name is used as internal string index name
Zebra internal index namezebra_[a-zA-Z](_?[a-zA-Z0-9])*hardwired internal string index name
XPATH special indexXPath/.*special xpath search for GRS indexed records
+ + + Attribute set names and + string index names are normalizes + according to the following rules: all single + hyphens '-' are stripped, and all upper case + letters are folded to lower case. + + + + Numeric use attributes are mapped + to the Zebra internal + string index according to the attribute set definition in use. + The default attribute set is Bib-1, and may be + omitted in the PQF query. + + + + According to normalization and numeric + use attribute mapping, it follows that the following + PQF queries are considered equivalent (assuming the default + configuration has not been altered): + + Z> find @attr 1=Body-of-text serenade + Z> find @attr 1=bodyoftext serenade + Z> find @attr 1=BodyOfText serenade + Z> find @attr 1=bO-d-Y-of-tE-x-t serenade + Z> find @attr 1=1010 serenade + Z> find @attrset Bib-1 @attr 1=1010 serenade + Z> find @attrset bib1 @attr 1=1010 serenade + Z> find @attrset Bib1 @attr 1=1010 serenade + Z> find @attrset b-I-b-1 @attr 1=1010 serenade + + + + + The numerical + use attributes (type 1) + are interpreted according to the + attribute sets which have been loaded in the + zebra.cfg file, and are matched against specific + fields as specified in the .abs file which + describes the profile of the records which have been loaded. + If no use attribute is provided, a default of + Bib-1 Use Any (1016) is + assumed. + The predefined use attribute sets + can be reconfigured by tweaking the configuration files + tab/*.att, and + new attribute sets can be defined by adding similar files in the + configuration path profilePath of the server. + + + + String indexes can be accessed directly, + independently which attribute set is in use. These are just + ignored. The above mentioned name normalization applies. + String index names are defined in the + used indexing filter configuration files, for example in the + GRS + *.abs configuration files, or in the + alvis filter XSLT indexing stylesheets. + + + + Zebra internal indexes can be accessed directly, + according to the same rules as the user defined + string indexes. The only difference is that + Zebra internal index names are hardwired, + all uppercase and + must start with the character '_'. + + + + Finally, XPATH access points are only + available using the GRS filter for indexing. + These access point names must start with the character + '/', they are not + normalized, but passed unaltered to the Zebra internal + XPATH engine. See . + + + + + + + + + Mapping of PQF APT structure and completeness to + register type + + Internally Zebra has in it's default configuration several + different types of registers or indexes, whose tokenization and + character normalization rules differ. This reflects the fact that + searching fundamental different tokens like dates, numbers, + bitfields and string based text needs different rule sets. + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
Structure and completeness mapping to register types
StructureCompletenessRegister typeNotes
+ phrase (@attr 4=1), word (@attr 4=2), + word-list (@attr 4=6), + free-form-text (@attr 4=105), or document-text (@attr 4=106) + Incomplete field (@attr 6=1)Word ('w')Traditional tokenized and character normalized word index
+ phrase (@attr 4=1), word (@attr 4=2), + word-list (@attr 4=6), + free-form-text (@attr 4=105), or document-text (@attr 4=106) + complete field' (@attr 6=3)Phrase ('p')Character normalized, but not tokenized index for phrase + matches +
urx (@attr 4=104)ignoredURX/URL ('u')Special index for URL web addresses
numeric (@attr 4=109)ignoredNumeric ('u')Special index for digital numbers
key (@attr 4=3)ignoredNull bitmap ('0')Used for non-tokenizated and non-normalized bit sequences
year (@attr 4=4)ignoredYear ('y')Non-tokenizated and non-normalized 4 digit numbers
date (@attr 4=5)ignoredDate ('d')Non-tokenizated and non-normalized ISO date strings
ignoredignoredSort ('s')Used with special sort attribute set (@attr 7=1, @attr 7=2)
overruledoverruledspecialInternal record ID register, used whenever + Relation Always Matches (@attr 2=103) is specified
+ + + + + If a Structure attribute of + Phrase is used in conjunction with a + Completeness attribute of + Complete (Sub)field, the term is matched + against the contents of the phrase (long word) register, if one + exists for the given Use attribute. + A phrase register is created for those fields in the + GRS *.abs file that contains a + p-specifier. + + Z> scan @attr 1=Title @attr 4=1 @attr 6=3 beethoven + ... + bayreuther festspiele (1) + * beethoven bibliography database (1) + benny carter (1) + ... + Z> find @attr 1=Title @attr 4=1 @attr 6=3 "beethoven bibliography" + ... + Number of hits: 0, setno 5 + ... + Z> find @attr 1=Title @attr 4=1 @attr 6=3 "beethoven bibliography database" + ... + Number of hits: 1, setno 6 + + + + + If Structure=Phrase is + used in conjunction with Incomplete Field - the + default value for 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 w in the GRS *.abs file. + + Z> scan @attr 1=Title @attr 4=1 @attr 6=1 beethoven + ... + beefheart (1) + * beethoven (18) + beethovens (7) + ... + Z> find @attr 1=Title @attr 4=1 @attr 6=1 beethoven + ... + Number of hits: 18, setno 1 + ... + Z> find @attr 1=Title @attr 4=1 @attr 6=1 "beethoven bibliography" + ... + Number of hits: 2, setno 2 + ... + + + + + If the Structure attribute is + Word List, + Free-form Text, or + 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 w in the + GRS *.abs file. + + + If the Structure attribute is + Numeric String the term is treated as an integer. + The search is performed on those fields that are indexed + as type n in the GRS + *.abs file. + + + + If the Structure attribute is + URX the term is treated as a URX (URL) entity. + The search is performed on those fields that are indexed as type + u in the *.abs file. + + + + If the Structure attribute is + Local Number the term is treated as + native Zebra Record Identifier. + + + + If the Relation attribute is + Equals (default), the term is matched + in a normal fashion (modulo truncation and processing of + individual words, if required). + If Relation is Less Than, + Less Than or Equal, + Greater than, or Greater than or + Equal, the term is assumed to be numerical, and a + standard regular expression is constructed to match the given + expression. + If Relation is Relevance, + the standard natural-language query processor is invoked. + + + + For the Truncation attribute, + No Truncation is the default. + Left Truncation is not supported. + Process # in search term is supported, as is + Regxp-1. + 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. + + + + + Zebra Regular Expressions in Truncation Attribute (type = 5) + + + Each term in a query is interpreted as a regular expression if + the truncation value is either Regxp-1 (@attr 5=102) + or Regxp-2 (@attr 5=103). + Both query types follow the same syntax with the operands: + + + + + + + + + + + + + + + + + + + + +
Regular Expression Operands
xMatches the character x.
.Matches any character.
[ .. ]Matches the set of characters specified; + such as [abc] or [a-c].
+ + + The above operands can be combined with the following operators: + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
Regular Expression Operators
x*Matches x zero or more times. + Priority: high.
x+Matches x one or more times. + Priority: high.
x? Matches x zero or once. + Priority: high.
xy Matches x, then y. + Priority: medium.
x|y Matches either x or y. + Priority: low.
( )The order of evaluation may be changed by using parentheses.
+ + + If the first character of the Regxp-2 query + is a plus character (+) 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. + + + + For example, a phrase search with regular expressions in + the title-register is performed like this: + + Z> find @attr 1=4 @attr 5=102 "informat.* retrieval" + + + + + Combinations with other attributes are possible. For example, a + ranked search with a regular expression: + + Z> find @attr 1=4 @attr 5=102 @attr 2=102 "informat.* retrieval" + + + - -