X-Git-Url: http://git.indexdata.com/?p=idzebra-moved-to-github.git;a=blobdiff_plain;f=doc%2Fquerymodel.xml;h=d7a7f8489ae6cbc385672497dc1fbcea1ecf9aeb;hp=71cca4dd8ff7374691d879fa486b224acd81c6c9;hb=693a0db94b4b3ac9aee7722572a6b81a86a12e13;hpb=d2f556b08050918081e72d18c73b817b9f41aaf9 diff --git a/doc/querymodel.xml b/doc/querymodel.xml index 71cca4d..d7a7f84 100644 --- a/doc/querymodel.xml +++ b/doc/querymodel.xml @@ -1,118 +1,113 @@ - Query Model - - Query Model Overview +
+ Query Model Overview - - +
Query Languages - Zebra is born as a networking Information Retrieval engine adhering + &zebra; is born as a networking Information Retrieval engine adhering to the international standards - Z39.50 and - SRU, + &acro.z3950; and + &acro.sru;, and implement the - type-1 Reverse Polish Notation (RPN) query + type-1 Reverse Polish Notation (&acro.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 + the &acro.z3950; protocol layer. This representation is not human readable, nor defines any convenient way to specify queries. - Since the type-1 (RPN) + Since the type-1 (&acro.rpn;) query structure has no direct, useful string - representation, every origin application needs to provide some + 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 representaion in the - Prefix Query Format, short - PQF, which mappes - one-to-one to binary encoded - type-1 RPN query packages. - It 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 explanaitions and - descriptions of Zebra's capabilities. - - - - Common Query Language (CQL) + + +
+ Prefix Query Format (&acro.pqf;) - The query model of the type-1 RPN, - expressed in PQF/PQN is natively supported. - On the other hand, the default SRU - webservices Common Query Language - CQL is not natively supported. + Index Data has defined a textual representation in the + Prefix Query Format, short + &acro.pqf;, which maps + one-to-one to binary encoded + type-1 &acro.rpn; queries. + &acro.pqf; has been adopted by other + parties developing &acro.z3950; software, and is often referred to as + Prefix Query Notation, or in short + &acro.pqn;. See + for further explanations and + descriptions of &zebra;'s capabilities. +
+ +
+ Common Query Language (&acro.cql;) - Zebra can be configured to understand and map CQL to PQF. See - . - - + The query model of the type-1 &acro.rpn;, + expressed in &acro.pqf;/&acro.pqn; is natively supported. + On the other hand, the default &acro.sru; + web services Common Query Language + &acro.cql; is not natively supported. + + + &zebra; can be configured to understand and map &acro.cql; to &acro.pqf;. See + . + +
- +
- +
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 + &zebra; supports all of the three different + &acro.z3950;/&acro.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. - +
Explain Operation - The syntax of Z39.50/SRU queries is + The syntax of &acro.z3950;/&acro.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 + explain operation, which provides the means for learning which fields (also called - indexes or access points + 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 embeddes the explain operation - by perfoming a - search in the magic + The &acro.z3950; embeds the explain operation + by performing a + search in the magic IR-Explain-1 database; see . - In SRU, explain is an entirely seperate - operation, which returns an Zeerex - XML record according to the + In &acro.sru;, explain is an entirely separate + operation, which returns an ZeeRex &acro.xml; record according to the structure defined by the protocol. In both cases, the information gathered through - explain operations can be used to + explain operations can be used to auto-configure a client user interface to the servers capabilities. - +
- + - +
Scan Operation - The scan operation is a helper functionality, + 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 handfull of terms actually fond in - the indexes, and in addition the scan - operation returns th enumber of documents indexed by each term. + 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 +
+ &acro.rpn; queries 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 &acro.pqf; grammar + is documented in the &yaz; manual, and shall not be + repeated here. This textual &acro.pqf; representation + is not transmitted to &zebra; during search, but it is in the + client mapped to the equivalent &acro.z3950; binary query parse tree. - - PQF tree structure +
+ &acro.rpn; tree structure - The PQF parse tree - or the equivalent textual representation - + The &acro.rpn; parse tree - or the equivalent textual representation in &acro.pqf; - may start with one specification of the attribute set used. Following is a query tree, which - consists of atomic query parts (APT), eventually + consists of atomic query parts (&acro.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 + 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 2-6 are hard-wired in. It is therefore essential - to be familiar with . - - - - - + + Attribute set + &acro.pqf; notation (Short hand) + Status + Notes + + + - - - - - - - - - - - - - - - + and semantics. + predefined + + + &acro.bib1; + bib-1 + Standard &acro.pqf; query language attribute set which defines the + semantics of &acro.z3950; searching. In addition, all of the + non-use attributes (types 2-14) define the hard-wired + &zebra; internal query + processing. + default + + + GILS + gils + Extension to the &acro.bib1; attribute set. + predefined + +
Attribute sets predefined in Zebra
exp-1Explain attribute setSpecial attribute set used on the special automagic + + Explain + exp-1 + Special 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.
- + + + The use attributes (type 1) mappings the + predefined attribute sets are found in the + attribute set configuration files tab/*.att. + + + + + The &zebra; internal query processing is modeled after + the &acro.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 subquery trees, or of atomic queries, is combined + 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. - - - - + + Keyword + Operator + Description + + - - - - - - - - - - - - - - - - + @and + binary AND operator + Set intersection of two atomic queries hit sets + + @or + binary OR operator + Set union of two atomic queries hit sets + + @not + binary AND NOT operator + Set complement of two atomic queries hit sets + + @prox + binary PROXIMITY operator + Set 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. + +
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.
@@ -277,7 +294,7 @@ 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. Z> find @and information retrieval @@ -287,120 +304,193 @@ 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. + The hit set is a subset of the corresponding + AND query + (see the &acro.pqf; grammar for + details on the proximity operator): - Z> find @prox information retrieval + 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. + 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 (&acro.apt;) - Atomic queries are the query parts which work on one acess point - only. These consist of an attribute list - followed by a single term or a - quoted term list, and are often called - Attributes-Plus-Terms (APT) queries. + 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, and are often called + Attributes-Plus-Terms (&acro.apt;) queries. - Unsupplied non-use attributes type 2-9 are either inherited from - higher nodes in the query tree, or are set to Zebra's default values. + Atomic (&acro.apt;) queries are always leaf nodes in the &acro.pqf; query tree. + UN-supplied non-use attributes types 2-12 are either inherited from + higher nodes in the query tree, or are set to &zebra;'s default values. See for details. - - - - - - - - - - - - + inherited, are set to the default &zebra; configuration values. + + + + term + single term + or quoted term list + Here the search terms or list of search terms is added + to the query + +
Atomic queries
attribute listList of orthogonal attributesAny of the orthogonal attribute types may be omitted, + + attribute list + List of orthogonal attributes + Any 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 - 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. - Z> find "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" + 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. - Z> find @attr 1=4 "" + Z> find @attr 1=4 debussy - + + The scan operation is only supported with + atomic &acro.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 + + +
- - Zebra's special use attribute type 1 of form 'string' + +
+ 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 &acro.pqf; query tree, exactly as + atomic &acro.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. + + - The numeric use (type 1) attribute is usually - refered to from a given - attribute set. In addition, Zebra let you use + 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 &acro.z3950; protocol. + The &acro.sru; web service is stateless, and therefore the notion of + named result sets does not exist when accessing a &zebra; server by + the &acro.sru; protocol. + + +
+ +
+ &zebra;'s special access point of type 'string' + + The numeric use (type 1) attribute is usually + 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 + 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 - the preferred way of accessing Zebra indexes directly. + 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 its internal full string + name. Scanning the same index. 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 its string name: 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 - indexation rules and can be parsed by the PQF parser. + It is possible to search + in any silly string index - if it's defined in your + indexing rules and can be parsed by the &acro.pqf; parser. This is definitely not the recommended use of this facility, as it might confuse your users with some very unexpected results. @@ -409,60 +499,62 @@ - See for details, and - - for the SRU PQF query extention using string names as a fast + See also for details, and + + for the &acro.sru; &acro.pqf; query extension using string names as a fast debugging facility. - +
- - Zebra's special use attribute type 1 of form 'XPath' - for GRS filters +
+ &zebra;'s special access point of type 'XPath' + for &acro.grs1; 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 appearence + 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 + be defined at indexing 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 acess. + gets populated from a possible entirely different &acro.xml; element + than it pretends to access. - When using the GRS Record Model - (see ), we have the + When using the &acro.grs1; Record Model + (see ), we have the possibility to embed life XPath expressions - in the PQF queries, which are here called - use (type 1) xpath + in the &acro.pqf; queries, which are here called + use (type 1) xpath attributes. You must enable the xpath enable directive in your - .abs config files. + .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. + + Only a very restricted subset of the + XPath 1.0 + standard is supported as the &acro.grs1; record model is simpler than + a full &acro.xml; &acro.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 + inside a text node found in a specific &acro.xml; &acro.dom; subtree, whose starting element is - adressed by XPath. + 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 decendant-or-self axis followed by a + XPath descendant-or-self axis followed by a text node selection text() is implicitly appended to the stated XPath. @@ -473,15 +565,25 @@ + + Searching inside attribute strings is possible: + + Z> find @attr 1=/link/@creator morten + + + - Filter the adressing XPath by a predicate working on exact + 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 subnodes of + attributes (in the &acro.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'] + /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 @@ -494,54 +596,55 @@ - Escaping PQF keywords and other non-parseable XPath constructs - with '{ }' to prevent syntax errors: + Escaping &acro.pqf; keywords and other non-parseable XPath constructs + with '{ }' to prevent client-side &acro.pqf; parsing + syntax errors: Z> find @attr {1=/root/first[@attr='danish']} content - Z> find @attr {1=/root/second[@attr='danish lake']} - Z> find @attr {1=/root/third[@attr='dansk s\xc3\xb8']} + Z> find @attr {1=/record/@set} oai - It is worth mentioning that these dynamic performed XPath - queries are a performance bottelneck, 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. + + 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 - The Z39.50 standard defines the - Explainattribute set - exp-1, which is used to discover information + The &acro.z3950; standard defines the + Explain attribute set + Exp-1, which is used to discover information about a server's search semantics and functional capabilities - Zebra exposes a "classic" + &zebra; exposes a "classic" Explain database by base name IR-Explain-1, which is populated with system internal information. 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, - Structure, Truncation, - and Completeness are imported from - the bib-1 attribute set, and may be used + &acro.bib1; attributes, that is, the types + Relation, Position, + Structure, Truncation, + and Completeness are imported from + the &acro.bib1; attribute set, and may be used within any explain query. - +
Use Attributes (type = 1) - The following Explain search atributes are supported: + The following Explain search attributes are supported: ExplainCategory (@attr 1=1), DatabaseName (@attr 1=3), DateAdded (@attr 1=9), @@ -555,20 +658,20 @@ See tab/explain.att and the - Z39.50 standard + &acro.z3950; 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 + via ASN.1. Practically no &acro.z3950; 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. + &acro.sutrs;, &acro.xml;, + &acro.grs1; and ASN.1 Explain. @@ -627,9 +730,9 @@ Get attribute details record for database Default. - This query is very useful to study the internal Zebra indexes. + This query is very useful to study the internal &zebra; indexes. If records have been indexed using the alvis - XSLT filter, the string representation names of the known indexes can be + &acro.xslt; filter, the string representation names of the known indexes can be found. Z> base IR-Explain-1 @@ -641,65 +744,89 @@ Z> find @attrset exp1 @and @attr 1=1 attributedetails @attr 1=3 Default - +
- +
- - Bib1 Attribute Set - - Something about querying to be written .. - +
+ &acro.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 + the ATTRIBUTE SET &acro.bib1; (&acro.z3950;-1995) SEMANTICS + found at . The &acro.bib1; Attribute Set Semantics from 1995, also in an updated - Bib-1 + &acro.bib1; Attribute Set version from 2003. Index Data is not the copyright holder of this - information. + information, except for the configuration details, the listing of + &zebra;'s capabilities, and the example queries. - +
Use Attributes (type 1) - A use attribute specifies an access point for any atomic query. - These acess points are highly dependent on the attribute set used + 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 &acro.bib1; 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. + be sourced in the main configuration zebra.cfg. - - In addition, Zebra allows the acess of + In addition, &zebra; allows the access of internal index names and dynamic - XPath as use attributes. - See and - for - alternative acess to the Zebra internal index names and XPath queries. + XPath as use attributes; see + and + . Phrase search for information retrieval in - the title-register: + the title-register, scanning the same register afterwards: Z> find @attr 1=4 "information retrieval" + Z> scan @attr 1=4 information +
- - +
+ + +
+ &zebra; general Bib1 Non-Use Attributes (type 2-6) + +
Relation Attributes (type 2) @@ -709,96 +836,149 @@ side of the relation), e.g., Date-publication <= 1975. - - - - - - - - - +
Relation Attributes (type 2)
RelationValueNotes
+ Relation Attributes (type 2) + + + + Relation + Value + Notes + - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - + + Less than + 1 + supported + + + Less than or equal + 2 + supported + + + Equal + 3 + default + + + Greater or equal + 4 + supported + + + Greater than + 5 + supported + + + Not equal + 6 + unsupported + + + Phonetic + 100 + unsupported + + + Stem + 101 + unsupported + + + Relevance + 102 + supported + + + AlwaysMatches + 103 + supported * + +
Less than1supported
Less than or equal2supported
Equal3default
Greater or equal4supported
Greater than5supported
Not equal6unsupported
Phonetic100unsupported
Stem101unsupported
Relevance102supported
AlwaysMatches103unsupported
+ + + AlwaysMatches searches are only supported if alwaysmatches indexing + has been enabled. See + + + + + The relation attributes 1-5 are supported and work exactly as + expected. + All ordering operations are based on a lexicographical ordering, + except 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 + + The relation attribute - relevance (102) is supported, see + Relevance (102) is supported, see for full information. - - - 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 - . - + + Ranked search for information retrieval in + the title-register: + + Z> find @attr 1=4 @attr 2=102 "information retrieval" + + - Ranked search for information retrieval in - the title-register: - - Z> find @attr 1=4 @attr 2=102 "information retrieval" - - - + 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 + &acro.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 "" + + - + +
+ +
Position Attributes (type 3) @@ -806,167 +986,208 @@ within the field or subfield in which it appears. - - - - - - - - - +
Position Attributes (type 3)
PositionValueNotes
+ Position Attributes (type 3) + + + + Position + Value + Notes + - - - - - - - - - - - - - - - + + First in field + 1 + supported * + + + First in subfield + 2 + supported * + + + Any position in field + 3 + default + +
First in field 1unsupported
First in subfield2unsupported
Any position in field3default
- - - The position attribute values first in field (1), - and first in subfield(2) are unsupported. - Using them does not trigger an error, but silent defaults to - any position in field (3). - + + + + &zebra; only supports first-in-field seaches if the + firstinfield is enabled for the index + Refer to . + &zebra; does not distinguish between first in field and + first in subfield. They result in the same hit count. + Searching for first position in (sub)field in only supported in &zebra; + 2.0.2 and later. - - - + +
+ +
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 + different &zebra; internal indexes, which must have been defined at index time. The possible values of the structure attribute (type 4) can be defined - using the configuraiton file - tab/default.idx. - The default configuration is summerized in this table. + using the configuration file tab/default.idx. + The default configuration is summarized in this table. - - - - - - - - - +
Structure Attributes (type 4)
StructureValueNotes
+ Structure Attributes (type 4) + + + + Structure + Value + Notes + - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - + + Phrase + 1 + default + + + Word + 2 + supported + + + Key + 3 + supported + + + Year + 4 + supported + + + Date (normalized) + 5 + supported + + + Word list + 6 + supported + + + Date (un-normalized) + 100 + unsupported + + + Name (normalized) + 101 + unsupported + + + Name (un-normalized) + 102 + unsupported + + + Structure + 103 + unsupported + + + Urx + 104 + supported + + + Free-form-text + 105 + supported + + + Document-text + 106 + supported + + + Local-number + 107 + supported + + + String + 108 + unsupported + + + Numeric string + 109 + supported + +
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
- - - The structure attribute value local-number - (107) - is supported, and maps always to the Zebra internal document ID. - + 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 &acro.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 + + + + + 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" + + - For example, in + 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 + + + + + In the GILS schema (gils.abs), the west-bounding-coordinate is indexed as type n, and is therefore searched by specifying @@ -976,206 +1197,411 @@ Z> find @attr 4=109 @attr 2=5 @attr gils 1=2038 -114 - + + + + The exact mapping between &acro.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 serch term and hit terms, 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
+ Truncation Attributes (type 5) + + + + Truncation + Value + Notes + - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - + + Right truncation + 1 + supported + + + Left truncation + 2 + supported + + + Left and right truncation + 3 + supported + + + Do not truncate + 100 + default + + + Process # in search term + 101 + supported + + + RegExpr-1 + 102 + supported + + + RegExpr-2 + 103 + supported + +
Right truncation 1supported
Left truncation2supported
Left and right truncation3supported
Do not truncate100default
Process # in search term101supported
RegExpr-1 102supported
RegExpr-2103supported
- Truncation attribute value - Process # in search term (100) is a + 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 - performes then a Regexp-1 (102) regular - expression search. + 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 + + - Truncation attribute value + The truncation attribute value Regexp-1 (102) is a normal regular search, - see. + 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 + + - Truncation attribute value - Regexp-2 (103) is a Zebra specific extention + 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 posiiton. + 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) - - This attribute is ONLY used if structure w, p is to be - chosen. completeness is ignorned if not w, p is to be - used.. - Incomplete field(1) is the default and makes Zebra use - register type w. - complete subfield(2) and complete field(3) both triggers - search field type p. - - - - - - Zebra specific Search Extentions to all Attribute Sets - - Zebra extends the Bib1 attribute types, and these extentions are - recognized regardless of attribute - set used in a search operation query. - - + + 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)). + - +
Zebra Search Attribute Extentions
+ Completeness Attributes (type = 6) + - - - - - - - + + Completeness + Value + Notes + + - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - + + Incomplete subfield + 1 + default + + + Complete subfield + 2 + deprecated + + + Complete field + 3 + supported + -
NameValueOperationZebra version
Embedded Sort7search1.1
Term Set8search1.1
Rank Weight9search1.1
Approx Limit9search1.4
Term Reference10search1.4
+ + - - Zebra Extention 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. - + + 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 reminiscent + from the happy &acro.marc; + binary format days. &zebra; does not support it, but maps silently + to Complete field (3). + + + + + The exact mapping between &acro.pqf; queries and &zebra; internal indexes + and index types is explained in + . + + +
+ +
+ +
+ +
+ Extended &zebra; &acro.rpn; 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 and higher values. + There are also the special + string type index names for the + idxpath attribute set. + + +
+ &zebra; specific retrieval of all records - 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 . - + &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). + - For example, searching for water, sort by title (ascending) + The _ALLRECORDS index name is used for total database + export. The search term is ignored, it may be empty. - Z> find @or @attr 1=1016 water @attr 7=1 @attr 1=4 0 + Z> find @attr 1=_ALLRECORDS @attr 2=103 "" - Or, searching for water, sort by title ascending, then date descending + 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 @or @or @attr 1=1016 water @attr 7=1 @attr 1=4 0 @attr 7=2 @attr 1=30 1 + 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 Scan Extensions to all Attribute Sets - For example, we might be intersted in exact hit count for a, but - for b we allow hit count estimates for 1000 and higher. - - Z> find @and a @attr 9=1000 b - + &zebra; extends the Bib1 attribute types, and these extensions are + recognized regardless of attribute + set used in a scan operation query. - - The estimated hit count fascility makes searches faster, as one - only needs to process large hit lists partially. - - - 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 - extention. Do not use in production code. - + + &zebra; Scan Attribute Extensions + + + + Name + Type + Operation + &zebra; version + + + + + Result Set Narrow + 8 + scan + 1.3 + + + Approximative Limit + 12 + scan + 2.0.20 + + + +
+ +
+ &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: + + 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) + ... + + + + + &zebra; 2.0.2 and later is able to skip 0 hit counts. This, however, + is known not to scale if the number of terms to skip is high. + This most likely will happen if the result set is small (and + result in many 0 hits). + +
- - Zebra Extention Term Reference Attribute (type 10) - +
+ &zebra; Extension Approximative Limit (type 12) + + The &zebra; Extension Approximative Limit (type 12) is a way to + enable approximate hit counts for scan hit counts, in the same + way as for search hit counts. + +
+
+ +
+ &zebra; special &acro.idxpath; Attribute Set for &acro.grs1; indexing - 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. + The attribute-set idxpath consists of a single + Use (type 1) attribute. All non-use attributes behave as normal. - - Experimental. Do not use in production code. + + The idxpath is deprecated, may not be + supported in future &zebra; versions, and should definitely + not be used in production code. + +
+ &acro.idxpath; Use Attributes (type = 1) + + This attribute set allows one to search &acro.grs1; filter indexed + records by &acro.xpath; like structured index names. + - - - - - Zebra specific Scan Extentions to all Attribute Sets - - Zebra extends the Bib1 attribute types, and these extentions are - recognized regardless of attribute - set used in a scan operation query. - - - - + + + The idxpath option defines hard-coded + index names, which might clash with your own index names. + + + +
Zebra Scan Attribute Extentions
+ &zebra; specific &acro.idxpath; Use Attributes (type 1) + - - - - - - - + + &acro.idxpath; + Value + String Index + Notes + + - - - - - - - - - - - - + + &acro.xpath; Begin + 1 + _XPATH_BEGIN + deprecated + + + &acro.xpath; End + 2 + _XPATH_END + deprecated + + + &acro.xpath; CData + 1016 + _XPATH_CDATA + deprecated + + + &acro.xpath; Attribute Name + 3 + _XPATH_ATTR_NAME + deprecated + + + &acro.xpath; Attribute CData + 1015 + _XPATH_ATTR_CDATA + deprecated + -
NameTypeOperationZebra version
Result Set Narrow8scan1.3
Approximative Limit9scan1.4
+ + + + + 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 &acro.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 &acro.xml; element node + including an &acro.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 '' + + - - Zebra Extention Result Set Narrow (type 8) - +
+
+ + +
+ Mapping from &acro.pqf; atomic &acro.apt; queries to &zebra; internal + register indexes - 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. + The rules for &acro.pqf; &acro.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. - - - Experimental and buggy. Definitely not to be used in production code. - - - Zebra Extention Approximative Limit (type 9) - - - The Zebra Extention Approximative Limit (type - 9) is a way to enable approx - hit counts for scan hit counts, in the same - way as for search hit counts. + + Access point name mapping + + + + Access Point + Type + Grammar + Notes + + + + + Use attribute + numeric + [1-9][1-9]* + directly mapped to string index name + + + String index name + string + [a-zA-Z](\-?[a-zA-Z0-9])* + normalized name is used as internal string index name + + + &zebra; internal index name + zebra + _[a-zA-Z](_?[a-zA-Z0-9])* + hardwired internal string index name + + + &acro.xpath; special index + XPath + /.* + special xpath search for &acro.grs1; 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 &acro.bib1;, and may be + omitted in the &acro.pqf; query. + + + + According to normalization and numeric + use attribute mapping, it follows that the following + &acro.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 bib1 @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 + - - - Experimental. Do not use in production code. - + + 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 + &acro.grs1; + *.abs configuration files, or in the + alvis filter &acro.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 '_'. + - - Mapping from Bib1 Attributes to Zebra internal - register indexes - - TO-DO - - - - + + Finally, &acro.xpath; access points are only + available using the &acro.grs1; filter for indexing. + These access point names must start with the character + '/', they are not + normalized, but passed unaltered to the &zebra; internal + &acro.xpath; engine. See . - + + + +
+ + +
+ Mapping of &acro.pqf; &acro.apt; structure and completeness to + register type - 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. - - + Internally &zebra; has in its 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 + + + + Structure + Completeness + Register type + Notes + + + + + + 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) + ignored + URX/URL ('u') + Special index for URL web addresses + + + numeric (@attr 4=109) + ignored + Numeric ('n') + Special index for digital numbers + + + key (@attr 4=3) + ignored + Null bitmap ('0') + Used for non-tokenized and non-normalized bit sequences + + + year (@attr 4=4) + ignored + Year ('y') + Non-tokenized and non-normalized 4 digit numbers + + + date (@attr 4=5) + ignored + Date ('d') + Non-tokenized and non-normalized ISO date strings + + + ignored + ignored + Sort ('s') + Used with special sort attribute set (@attr 7=1, @attr 7=2) + + + overruled + overruled + special + Internal 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 @@ -1441,9 +2213,23 @@ 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 + &acro.grs1; *.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 + @@ -1454,7 +2240,23 @@ 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. + type w in the &acro.grs1; *.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 + ... + @@ -1465,27 +2267,28 @@ 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. + &acro.grs1; *.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. + as type n in the &acro.grs1; + *.abs file. If the Structure attribute is - URx the term is treated as a URX (URL) entity. + 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. + u in the *.abs file. If the Structure attribute is Local Number the term is treated as - native Zebra Record Identifier. + native &zebra; Record Identifier. @@ -1514,10 +2317,12 @@ replacement) is accepted when terms are matched against the register contents. - - - Zebra Regular Expressions in Truncation Attribute (type = 5) +
+
+ +
+ &zebra; Regular Expressions in Truncation Attribute (type = 5) Each term in a query is interpreted as a regular expression if @@ -1526,84 +2331,77 @@ 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].
+ + Regular Expression Operands + + + + x + Matches 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.
- + + + 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, + Currently &zebra; only supports one specifier, the error tolerance, which consists one digit. + @@ -1627,40 +2425,40 @@ Z> find @attr 1=4 @attr 5=102 @attr 2=102 "informat.* retrieval" - +
- + - - Server Side CQL to PQF Query Translation +
+ Server Side &acro.cql; to &acro.pqf; Query Translation Using the <cql2rpn>l2rpn.txt</cql2rpn> - YAZ Frontend Virtual + &yaz; Frontend Virtual Hosts option, one can configure - the YAZ Frontend CQL-to-PQF + the &yaz; Frontend &acro.cql;-to-&acro.pqf; converter, specifying the interpretation of various - CQL + &acro.cql; indexes, relations, etc. in terms of Type-1 query attributes. - For example, using server-side CQL-to-PQF conversion, one might + For example, using server-side &acro.cql;-to-&acro.pqf; conversion, one might query a zebra server like this: and - if properly configured - even static relevance ranking can - be performed using CQL query syntax: + be performed using &acro.cql; query syntax: find text = /relevant (plant and soil) @@ -1680,7 +2478,7 @@ By the way, the same configuration can be used to - search using client-side CQL-to-PQF conversion: + search using client-side &acro.cql;-to-&acro.pqf; conversion: (the only difference is querytype cql2rpn instead of querytype cql, and the call specifying a local @@ -1696,24 +2494,19 @@ Exhaustive information can be found in the - Section "Specification of CQL to RPN mappings" in the YAZ manual. - - http://www.indexdata.dk/yaz/doc/tools.tkl#tools.cql.map, - and shall therefore not be repeated here. + Section &acro.cql; to &acro.rpn; conversion + in the &yaz; manual. - - - +