<chapter id="querymodel">
- <!-- $Id: querymodel.xml,v 1.5 2006-06-14 13:57:45 marc Exp $ -->
+ <!-- $Id: querymodel.xml,v 1.16 2006-06-25 21:54:03 marc Exp $ -->
<title>Query Model</title>
<sect1 id="querymodel-overview">
- <title>Query Model Overview</title>
-
+ <title>Query Model Overview</title>
<sect2 id="querymodel-query-languages">
<title>Query Languages</title>
to the international standards
<ulink url="&url.z39.50;">Z39.50</ulink> and
<ulink url="&url.sru;">SRU</ulink>,
- and implement the query model defined there.
- Unfortunately, the Z39.50 query model has only defined a binary
+ and implement the
+ <literal>type-1 Reverse Polish Notation (RPN)</literal> 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.
</para>
- <!-- tell about RPN - include link to YAZ
- url.yaz.pqf -->
+ <para>
+ Since the <literal>type-1 (RPN)</literal>
+ query structure has no direct, useful string
+ representation, every origin application needs to provide some
+ form of mapping from a local query notation or representation to it.
+ </para>
+
<sect3 id="querymodel-query-languages-pqf">
<title>Prefix Query Format (PQF)</title>
<para>
- Index Data has defined a textual representaion in the
+ Index Data has defined a textual representation in the
<literal>Prefix Query Format</literal>, short
- <literal>PQF</literal>, which then has been adopted by other
- parties developing Z39.50 software. It is also often referred to as
+ <literal>PQF</literal>, which maps
+ <literal>one-to-one</literal> to binary encoded
+ <literal>type-1 RPN</literal> query packages.
+ It has been adopted by other
+ parties developing Z39.50 software, and is often referred to as
<literal>Prefix Query Notation</literal>, or in short
- <literal>PQN</literal>, and is thoroughly explained in
- <xref linkend="querymodel-pqf"/>.
+ <literal>PQN</literal>. See
+ <xref linkend="querymodel-pqf"/> for further explanations and
+ descriptions of Zebra's capabilities.
</para>
</sect3>
-
- <!-- PQF/RPN is natively supported. CQL is NOT . So we need a map -->
<sect3 id="querymodel-query-languages-cql">
<title>Common Query Language (CQL)</title>
- <para>
- In addition, Zebra can be configured to understand and map the
- <literal>Common Query Language</literal>
- (<ulink url="&url.cql;">CQL</ulink>)
- to PQF. See an introduction on the mapping to the internal query
- representation in
+ <para>
+ The query model of the <literal>type-1 RPN</literal>,
+ expressed in <literal>PQF/PQN</literal> is natively supported.
+ On the other hand, the default <literal>SRU</literal>
+ webservices <literal>Common Query Language</literal>
+ <ulink url="&url.cql;">CQL</ulink> is not natively supported.
+ </para>
+ <para>
+ Zebra can be configured to understand and map CQL to PQF. See
<xref linkend="querymodel-cql-to-pqf"/>.
</para>
</sect3>
</sect2>
- <sect2 id="querymodel-query-types">
- <title>Query types</title>
+ <sect2 id="querymodel-operation-types">
+ <title>Operation types</title>
<para>
+ Zebra supports all of the three different
+ <literal>Z39.50/SRU</literal> operations defined in the
+ standards: <literal>explain</literal>, <literal>search</literal>,
+ and <literal>scan</literal>. A short description of the
+ functionality and purpose of each is quite in order here.
</para>
- <sect3 id="querymodel-query-type-explain">
- <title>Explain Queries</title>
+ <sect3 id="querymodel-operation-type-explain">
+ <title>Explain Operation</title>
+ <para>
+ The <emphasis>syntax</emphasis> of Z39.50/SRU queries is
+ well known to any client, but the specific
+ <emphasis>semantics</emphasis> - taking into account a
+ particular servers functionalities and abilities - must be
+ discovered from case to case. Enters the
+ <literal>explain</literal> operation, which provides the means
+ for learning which
+ <emphasis>fields</emphasis> (also called
+ <emphasis>indexes</emphasis> or <emphasis>access points</emphasis>
+ 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.
+ </para>
+ <para>
+ The Z39.50 embeds the <literal>explain</literal> operation
+ by performing a
+ <literal>search</literal> in the magic
+ <literal>IR-Explain-1</literal> database;
+ see <xref linkend="querymodel-exp1"/>.
+ </para>
+ <para>
+ In SRU, <literal>explain</literal> is an entirely separate
+ operation, which returns an <literal>ZeeRex
+ XML</literal> record according to the
+ structure defined by the protocol.
+ </para>
<para>
+ In both cases, the information gathered through
+ <literal>explain</literal> operations can be used to
+ auto-configure a client user interface to the servers
+ capabilities.
</para>
</sect3>
- <sect3 id="querymodel-query-type-search">
- <title>Search Queries</title>
+ <sect3 id="querymodel-operation-type-search">
+ <title>Search Operation</title>
<para>
+ 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.
</para>
</sect3>
- <sect3 id="querymodel-query-type-scan">
- <title>Scan Queries</title>
+ <sect3 id="querymodel-operation-type-scan">
+ <title>Scan Operation</title>
+ <para>
+ The <literal>scan</literal> operation is a helper functionality,
+ which operates on one index or access point a time.
+ </para>
<para>
+ It provides
+ the means to investigate the content of specific indexes.
+ Scanning an index returns a handful of terms actually fond in
+ the indexes, and in addition the <literal>scan</literal>
+ 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.
</para>
</sect3>
<sect1 id="querymodel-pqf">
- <title>Prefix Query Format structure and syntax</title>
+ <title>Prefix Query Format syntax and semantics</title>
<para>
The <ulink url="&url.yaz.pqf;">PQF grammer</ulink>
is documented in the YAZ manual, and shall not be
may start with one specification of the
<emphasis>attribute set</emphasis> used. Following is a query
tree, which
- consists of <emphasis>atomic query parts</emphasis>, eventually
+ consists of <emphasis>atomic query parts (APT)</emphasis> or
+ <emphasis>named result sets</emphasis>, eventually
paired by <emphasis>boolean binary operators</emphasis>, and
finally <emphasis>recursively combined </emphasis> into
complex query trees.
issued. Zebra comes with some predefined attribute set
definitions, others can easily be defined and added to the
configuration.
- <note>
- The Zebra internal query procesing is modeled after
- the <literal>Bib1</literal> attribute set, and the non-use
- attributes type 2-6 are hard-wired in. It is therefore essential
- to be familiar with <xref linkend="querymodel-bib1"/>.
- </note>
</para>
+
- <table id="querymodel-attribute-sets-table">
+ <table id="querymodel-attribute-sets-table"
+ frame="all" rowsep="1" colsep="1" align="center">
+
<caption>Attribute sets predefined in Zebra</caption>
- <!--
+
<thead>
- <tr><td>one</td><td>two</td></tr>
+ <tr>
+ <td>Attribute set</td>
+ <td>Short hand</td>
+ <td>Status</td>
+ <td>Notes</td>
+ </tr>
</thead>
- -->
+
<tbody>
<tr>
- <td><emphasis>exp-1</emphasis></td>
- <td><literal>Explain</literal> attribute set</td>
+ <td><literal>Explain</literal></td>
+ <td><literal>exp-1</literal></td>
<td>Special attribute set used on the special automagic
<literal>IR-Explain-1</literal> database to gain information on
server capabilities, database names, and database
and semantics.</td>
+ <td>predefined</td>
</tr>
<tr>
- <td><emphasis>bib-1</emphasis></td>
- <td><literal>Bib1</literal> attribute set</td>
+ <td><literal>Bib1</literal></td>
+ <td><literal>bib-1</literal></td>
<td>Standard 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</td>
+ non-use attributes (type 2-9) define the hard-wired
+ Zebra internal query
+ processing.</td>
+ <td>default</td>
</tr>
<tr>
- <td><emphasis>gils</emphasis></td>
- <td><literal>GILS</literal> attribute set</td>
- <td>Extention to the <literal>Bib1</literal> attribute set.</td>
+ <td><literal>GILS</literal></td>
+ <td><literal>gils</literal></td>
+ <td>Extension to the <literal>Bib1</literal> attribute set.</td>
+ <td>predefined</td>
</tr>
+ <!--
+ <tr>
+ <td><literal>IDXPATH</literal></td>
+ <td><literal>idxpath</literal></td>
+ <td>Hardwired XPATH like attribute set, only available for
+ indexing with the GRS record model</td>
+ <td>depreciated</td>
+ </tr>
+ -->
</tbody>
</table>
</sect3>
+
+ <para>
+ The <literal>use attributes (type 1)</literal> mappings the
+ predefined attribute sets are found in the
+ attribute set configuration files <filename>tab/*.att</filename>.
+ </para>
+
+ <note>
+ The Zebra internal query processing is modeled after
+ the <literal>Bib1</literal> attribute set, and the non-use
+ attributes type 2-6 are hard-wired in. It is therefore essential
+ to be familiar with <xref linkend="querymodel-bib1-nonuse"/>.
+ </note>
+
<sect3 id="querymodel-boolean-operators">
<title>Boolean operators</title>
<para>
A pair of subquery 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.
</para>
- <table id="querymodel-boolean-operators-table">
+ <table id="querymodel-boolean-operators-table"
+ frame="all" rowsep="1" colsep="1" align="center">
+
<caption>Boolean operators</caption>
- <!--
<thead>
- <tr><td>one</td><td>two</td></tr>
+ <tr>
+ <td>Keyword</td>
+ <td>Operator</td>
+ <td>Description</td>
+ </tr>
</thead>
- -->
<tbody>
- <tr><td><emphasis>@and</emphasis></td>
+ <tr><td><literal>@and</literal></td>
<td>binary <literal>AND</literal> operator</td>
<td>Set intersection of two atomic queries hit sets</td>
</tr>
- <tr><td><emphasis>@or</emphasis></td>
+ <tr><td><literal>@or</literal></td>
<td>binary <literal>OR</literal> operator</td>
<td>Set union of two atomic queries hit sets</td>
</tr>
- <tr><td><emphasis>@not</emphasis></td>
+ <tr><td><literal>@not</literal></td>
<td>binary <literal>AND NOT</literal> operator</td>
<td>Set complement of two atomic queries hit sets</td>
</tr>
- <tr><td><emphasis>@prox</emphasis></td>
+ <tr><td><literal>@prox</literal></td>
<td>binary <literal>PROXIMY</literal> operator</td>
<td>Set intersection of two atomic queries hit sets. In
addition, the intersection set is purged for all
Querying for the intersection of all documents containing the
terms <emphasis>information</emphasis> AND
<emphasis>retrieval</emphasis>:
- The hit set is a subset of the coresponding
+ The hit set is a subset of the corresponding
OR query.
<screen>
Z> find @and information retrieval
Querying for the intersection of all documents containing the
terms <emphasis>information</emphasis> AND
<emphasis>retrieval</emphasis>, 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 <ulink url="&url.yaz.pqf;">PQF grammar</ulink> for
+ details on the proximity operator):
<screen>
- Z> find @prox information retrieval
+ Z> find @prox 0 3 0 2 k 2 information retrieval
</screen>
</para>
<para>
Querying for the intersection of all documents containing the
terms <emphasis>information</emphasis> AND
<emphasis>retrieval</emphasis>, in the same order and near each
- other as described in the term list
- The hit set is a subset of the coresponding
+ other as described in the term list.
+ The hit set is a subset of the corresponding
PROXIMY query.
<screen>
Z> find "information retrieval"
<sect3 id="querymodel-atomic-queries">
- <title>Atomic queries</title>
+ <title>Atomic queries (APT)</title>
<para>
- Atomic queries are the query parts which work on one acess point
+ Atomic queries are the query parts which work on one access point
only. These consist of <literal>an attribute list</literal>
followed by a <literal>single term</literal> or a
- <literal>quoted term list</literal>.
+ <literal>quoted term list</literal>, and are often called
+ <emphasis>Attributes-Plus-Terms (APT)</emphasis> queries.
</para>
<para>
+ Atomic (APT) queries are always leaf nodes in the PQF query tree.
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.
See <xref linkend="querymodel-bib1"/> for details.
</para>
- <table id="querymodel-atomic-queries-table">
- <caption>Atomic queries</caption>
- <!--
+ <table id="querymodel-atomic-queries-table"
+ frame="all" rowsep="1" colsep="1" align="center">
+
+ <caption>Atomic queries (APT)</caption>
<thead>
- <tr><td>one</td><td>two</td></tr>
+ <tr>
+ <td>Name</td>
+ <td>Type</td>
+ <td>Notes</td>
+ </tr>
</thead>
- -->
<tbody>
- <tr><td><emphasis>attribute list</emphasis></td>
+ <tr>
+ <td><emphasis>attribute list</emphasis></td>
<td>List of <literal>orthogonal</literal> attributes</td>
<td>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.
</td>
</tr>
- <tr><td><emphasis>term</emphasis></td>
+ <tr>
+ <td><emphasis>term</emphasis></td>
<td>single <literal>term</literal>
or <literal>quoted term list</literal> </td>
<td>Here the search terms or list of search terms is added
</table>
<para>
Querying for the term <emphasis>information</emphasis> 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.
<screen>
- Z> find "information"
+ Z> find information
</screen>
</para>
<para>
- Equivalent query fully specified:
+ Equivalent query fully specified including all default values:
<screen>
- 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
</screen>
</para>
-
+
<para>
- 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
+ <emphasis>debussy</emphasis> in the title field.
<screen>
- Z> find @attr 1=4 ""
+ Z> find @attr 1=4 debussy
</screen>
</para>
+ <para>
+ The <literal>scan</literal> 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
+ <literal>scan</literal>.
+ </para>
+
+ <para>
+ For example, we migh want to scan the title index, starting with
+ the term
+ <emphasis>debussy</emphasis>, and displaying this and the
+ following terms in lexicographic order:
+ <screen>
+ Z> scan @attr 1=4 debussy
+ </screen>
+ </para>
</sect3>
+
+ <sect3 id="querymodel-resultset">
+ <title>Named Result Sets</title>
+ <para>
+ 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.
+ </para>
+ <para>
+ 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.
+ </para>
+
+ <para>
+ Defining a named result set and re-using it in the next query,
+ using <literal>yaz-client</literal>.
+ <screen>
+ 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
+ ...
+ Z> f @attr 1=1016 beethoven
+ ...
+ Number of hits: 26, setno 3
+ ...
+ </screen>
+ </para>
+
+ <note>
+ 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.
+ </note>
+ </sect3>
+
+
<sect3 id="querymodel-use-string">
- <title>Zebra's special use attribute type 1 of form 'string'</title>
+ <title>Zebra's special access point of type 'string'</title>
<para>
The numeric <literal>use (type 1)</literal> attribute is usually
- refered to from a given
+ referred to from a given
attribute set. In addition, Zebra let you use
<emphasis>any internal index
name defined in your configuration</emphasis>
- 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
+ not need the complexity of defined use attribute values. It is
the preferred way of accessing Zebra indexes directly.
</para>
<para>
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.
<screen>
Z> find @attr 1=sometext "information retrieval"
+ Z> scan @attr 1=sometext aterm
</screen>
</para>
<para>
- 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:
<screen>
Z> find @attr 1=Code-language eng
+ Z> scan @attr 1=Code-language ""
</screen>
</para>
<para>
- 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
</screen>
</para>
<para>
- See <xref linkend="querymodel-bib1-mapping"/> for details, and
+ See also <xref linkend="querymodel-pqf-apt-mapping"/> for details, and
<xref linkend="server-sru"/>
- for the SRU PQF query extention using string names as a fast
+ for the SRU PQF query extension using string names as a fast
debugging facility.
</para>
</sect3>
<sect3 id="querymodel-use-xpath">
- <title>Zebra's special use attribute type 1 of form 'XPath'
+ <title>Zebra's special access point of type 'XPath'
for GRS filters</title>
<para>
As we have seen above, it is possible (albeit seldom a great
idea) to emulate
<ulink url="http://www.w3.org/TR/xpath">XPath 1.0</ulink> based
search by defining <literal>use (type 1)</literal>
- <emphasis>string</emphasis> attributes which in appearence
+ <emphasis>string</emphasis> attributes which in appearance
<emphasis>resemble XPath queries</emphasis>. 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 acess.
+ than it pretends to access.
</para>
<para>
When using the <literal>GRS Record Model</literal>
<literal>use (type 1)</literal> <emphasis>xpath</emphasis>
attributes. You must enable the
<literal>xpath enable</literal> directive in your
- <literal>.abs</literal> config files.
+ <literal>.abs</literal> configuration files.
</para>
<note>
Only a <emphasis>very</emphasis> restricted subset of the
Finding all documents which have the term "content"
inside a text node found in a specific XML DOM
<emphasis>subtree</emphasis>, whose starting element is
- adressed by XPath.
+ addressed by XPath.
<screen>
Z> find @attr 1=/root content
Z> find @attr 1=/root/first content
</screen>
<emphasis>Notice that the
XPath must be absolute, i.e., must start with '/', and that the
- XPath <literal>decendant-or-self</literal> axis followed by a
+ XPath <literal>descendant-or-self</literal> axis followed by a
text node selection <literal>text()</literal> is implicitly
appended to the stated XPath.
</emphasis>
</screen>
</para>
+ <para>
+ Searching inside attribute strings is possible:
+ <screen>
+ Z> find @attr 1=/link/@creator morten
+ </screen>
+ </para>
+
<para>
- 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
the subtree defined by the XPath
- <literal>/record/title[@lang='en']</literal>
+ <literal>/record/title[@lang='en']</literal>. And similar
+ predicate filtering.
<screen>
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
</screen>
</para>
with <literal>'{ }'</literal> to prevent syntax errors:
<screen>
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
</screen>
</para>
<warning>
It is worth mentioning that these dynamic performed XPath
- queries are a performance bottelneck, as no optimized
+ 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.
</warning>
+
</sect3>
</sect2>
<title>Explain Attribute Set</title>
<para>
The Z39.50 standard defines the
- <ulink url="&url.z39.50.explain;">Explain</ulink>attribute set
- <literal>exp-1</literal>, which is used to discover information
+ <ulink url="&url.z39.50.explain;">Explain</ulink> attribute set
+ <literal>Exp-1</literal>, which is used to discover information
about a server's search semantics and functional capabilities
Zebra exposes a "classic"
Explain database by base name <literal>IR-Explain-1</literal>, which
</para>
<para>
The attribute-set <literal>exp-1</literal> consists of a single
- <literal>Use (type 1)</literal> attribute.
+ <literal>use attribute (type 1)</literal>.
</para>
<para>
In addition, the non-Use
<sect3 id="querymodel-exp1-use">
<title>Use Attributes (type = 1)</title>
<para>
- The following Explain search atributes are supported:
+ The following Explain search attributes are supported:
<literal>ExplainCategory</literal> (@attr 1=1),
<literal>DatabaseName</literal> (@attr 1=3),
<literal>DateAdded</literal> (@attr 1=9),
<title>Explain searches with yaz-client</title>
<para>
Classic Explain only defines retrieval of Explain information
- via ASN.1. Pratically no Z39.50 clients supports this. Fortunately
+ 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:
<literal>SUTRS</literal>, <literal>XML</literal>,
<sect2 id="querymodel-bib1">
<title>Bib1 Attribute Set</title>
<para>
- Something about querying to be written ..
- </para>
- <para>
Most of the information contained in this section is an excerpt of
the <literal>ATTRIBUTE SET BIB-1 (Z39.50-1995)
SEMANTICS</literal>,
- found at <ulink url="&url.z39.50.attset.bib1.1995;">. The BIB-1
+ found at <ulink url="&url.z39.50.attset.bib1.1995;">. The BIB-1
Attribute Set Semantics</ulink> from 1995, also in an updated
<ulink url="&url.z39.50.attset.bib1;">Bib-1
Attribute Set</ulink>
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.
</para>
<sect3 id="querymodel-bib1-use">
- <title>Use Attributes (type = 1)</title>
- </sect3>
+ <title>Use Attributes (type 1)</title>
+
+ <para>
+ 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:
+ <filename>tab/bib1.att</filename>,
+ <filename>tab/dan1.att</filename>,
+ <filename>tab/explain.att</filename>, and
+ <filename>tab/gils.att</filename>.
+ New attribute sets can be added by adding new
+ <filename>tab/*.att</filename> configuration files, which need to
+ be sourced in the main configuration <filename>zebra.cfg</filename>.
+ </para>
+
+ <para>
+ In addition, Zebra allows the access of
+ <emphasis>internal index names</emphasis> and <emphasis>dynamic
+ XPath</emphasis> as use attributes; see
+ <xref linkend="querymodel-use-string"/> and
+ <xref linkend="querymodel-use-xpath"/>.
+ </para>
<para>
Phrase search for <emphasis>information retrieval</emphasis> in
- the title-register:
+ the title-register, scanning the same register afterwards:
<screen>
Z> find @attr 1=4 "information retrieval"
+ Z> scan @attr 1=4 information
</screen>
</para>
+ </sect3>
+
+ </sect2>
- <para>
- See also <xref linkend="querymodel-use-string and "/>
- <xref linkend="querymodel-use-xpath"/> for
- alternative acess to the Zebra internal index names and XPath queries.
- </para>
+ <sect2 id="querymodel-bib1-nonuse">
+ <title>Zebra general Bib1 Non-Use Attributes (type 2-6)</title>
<sect3 id="querymodel-bib1-relation">
- <title>Relation Attributes (type = 2)</title>
- <para>
- Supported operations: = (default, of omitted), < > <=, >= .
- Unsupported: Not equal.
+ <title>Relation Attributes (type 2)</title>
- The following relation attributes are also supported: relevance (102).
- <!-- always-matches (103) not supported for all indexes -->
+ <para>
+ 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.
+ </para>
+
+ <table id="querymodel-bib1-relation-table"
+ frame="all" rowsep="1" colsep="1" align="center">
+
+ <caption>Relation Attributes (type 2)</caption>
+ <thead>
+ <tr>
+ <td>Relation</td>
+ <td>Value</td>
+ <td>Notes</td>
+ </tr>
+ </thead>
+ <tbody>
+ <tr>
+ <td> Less than</td>
+ <td>1</td>
+ <td>supported</td>
+ </tr>
+ <tr>
+ <td>Less than or equal</td>
+ <td>2</td>
+ <td>supported</td>
+ </tr>
+ <tr>
+ <td>Equal</td>
+ <td>3</td>
+ <td>default</td>
+ </tr>
+ <tr>
+ <td>Greater or equal</td>
+ <td>4</td>
+ <td>supported</td>
+ </tr>
+ <tr>
+ <td>Greater than</td>
+ <td>5</td>
+ <td>supported</td>
+ </tr>
+ <tr>
+ <td>Not equal</td>
+ <td>6</td>
+ <td>unsupported</td>
+ </tr>
+ <tr>
+ <td>Phonetic</td>
+ <td>100</td>
+ <td>unsupported</td>
+ </tr>
+ <tr>
+ <td>Stem</td>
+ <td>101</td>
+ <td>unsupported</td>
+ </tr>
+ <tr>
+ <td>Relevance</td>
+ <td>102</td>
+ <td>supported</td>
+ </tr>
+ <tr>
+ <td>AlwaysMatches</td>
+ <td>103</td>
+ <td>supported</td>
+ </tr>
+ </tbody>
+ </table>
+
+ <para>
+ The relation attributes
+ <literal>1-5</literal> are supported and work exactly as
+ expected.
+ All ordering operations are based on a lexicographical ordering,
+ <emphasis>expect</emphasis> when the
+ <literal>structure attribute numeric (109)</literal> is used. In
+ this case, ordering is numerical. See
+ <xref linkend="querymodel-bib1-structure"/>.
+ <screen>
+ 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
+ </screen>
+ </para>
+
+ <para>
+ The relation attribute
+ <literal>Relevance (102)</literal> is supported, see
+ <xref linkend="administration-ranking"/> for full information.
+ </para>
+
+ <para>
+ Ranked search for <emphasis>information retrieval</emphasis> in
+ the title-register:
+ <screen>
+ Z> find @attr 1=4 @attr 2=102 "information retrieval"
+ </screen>
+ </para>
+
+ <para>
+ The relation attribute
+ <literal>AlwaysMatches (103)</literal> is in the default
+ configuration
+ supported in conjecture with structure attribute
+ <literal>Phrase (1)</literal> (which may be omitted by
+ default).
+ It can be configured to work with other structure attributes,
+ see the configuration file
+ <filename>tab/default.idx</filename> and
+ <xref linkend="querymodel-pqf-apt-mapping"/>.
+ </para>
+ <para>
+ <literal>AlwaysMatches (103)</literal> 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.
+ <screen>
+ Z> find @attr 1=Title @attr 2=103 ""
+ Z> find @attr 1=Title @attr 2=103 @attr 4=1 ""
+ </screen>
+ </para>
- All operations are based on a lexicographical ordering,
- <emphasis>expect</emphasis> in the case for the
- following structure attributes: numeric(109).
- </para>
- <para>
- Ranked search for <emphasis>information retrieval</emphasis> in
- the title-register
- (see <xref linkend="administration-ranking"/> for the glory details):
- <screen>
- Z> find @attr 1=4 @attr 2=102 "information retrieval"
- </screen>
- </para>
</sect3>
<sect3 id="querymodel-bib1-position">
- <title>Position Attributes (type = 3)</title>
+ <title>Position Attributes (type 3)</title>
+
<para>
- Only value of (any position(3) is supported. first in field(1),
- and first in subfield(2) are unsupported but using them
- does not trigger an error.
+ The position attribute specifies the location of the search term
+ within the field or subfield in which it appears.
+ </para>
+
+ <table id="querymodel-bib1-position-table"
+ frame="all" rowsep="1" colsep="1" align="center">
+
+ <caption>Position Attributes (type 3)</caption>
+ <thead>
+ <tr>
+ <td>Position</td>
+ <td>Value</td>
+ <td>Notes</td>
+ </tr>
+ </thead>
+ <tbody>
+ <tr>
+ <td>First in field </td>
+ <td>1</td>
+ <td>unsupported</td>
+ </tr>
+ <tr>
+ <td>First in subfield</td>
+ <td>2</td>
+ <td>unsupported</td>
+ </tr>
+ <tr>
+ <td>Any position in field</td>
+ <td>3</td>
+ <td>default</td>
+ </tr>
+ </tbody>
+ </table>
+
+ <para>
+ The position attribute values <literal>first in field (1)</literal>,
+ and <literal>first in subfield(2)</literal> are unsupported.
+ Using them does not trigger an error, but silent defaults to
+ <literal>any position in field (3)</literal>.
<!-- It should -->
</para>
</sect3>
<sect3 id="querymodel-bib1-structure">
- <title>Structure Attributes (type = 4)</title>
- <!-- See tab/default.idx -->
- </sect3>
+ <title>Structure Attributes (type 4)</title>
+
+ <para>
+ 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.
+ </para>
+
+ <para>
+ The possible values of the
+ <literal>structure attribute (type 4)</literal> can be defined
+ using the configuration file <filename>
+ tab/default.idx</filename>.
+ The default configuration is summarized in this table.
+ </para>
+
+ <table id="querymodel-bib1-structure-table"
+ frame="all" rowsep="1" colsep="1" align="center">
+
+ <caption>Structure Attributes (type 4)</caption>
+ <thead>
+ <tr>
+ <td>Structure</td>
+ <td>Value</td>
+ <td>Notes</td>
+ </tr>
+ </thead>
+ <tbody>
+ <tr>
+ <td>Phrase </td>
+ <td>1</td>
+ <td>default</td>
+ </tr>
+ <tr>
+ <td>Word</td>
+ <td>2</td>
+ <td>supported</td>
+ </tr>
+ <tr>
+ <td>Key</td>
+ <td>3</td>
+ <td>supported</td>
+ </tr>
+ <tr>
+ <td>Year</td>
+ <td>4</td>
+ <td>supported</td>
+ </tr>
+ <tr>
+ <td>Date (normalized)</td>
+ <td>5</td>
+ <td>supported</td>
+ </tr>
+ <tr>
+ <td>Word list</td>
+ <td>6</td>
+ <td>supported</td>
+ </tr>
+ <tr>
+ <td>Date (un-normalized)</td>
+ <td>100</td>
+ <td>unsupported</td>
+ </tr>
+ <tr>
+ <td>Name (normalized) </td>
+ <td>101</td>
+ <td>unsupported</td>
+ </tr>
+ <tr>
+ <td>Name (un-normalized) </td>
+ <td>102</td>
+ <td>unsupported</td>
+ </tr>
+ <tr>
+ <td>Structure</td>
+ <td>103</td>
+ <td>unsupported</td>
+ </tr>
+ <tr>
+ <td>Urx</td>
+ <td>104</td>
+ <td>supported</td>
+ </tr>
+ <tr>
+ <td>Free-form-text</td>
+ <td>105</td>
+ <td>supported</td>
+ </tr>
+ <tr>
+ <td>Document-text</td>
+ <td>106</td>
+ <td>supported</td>
+ </tr>
+ <tr>
+ <td>Local-number</td>
+ <td>107</td>
+ <td>supported</td>
+ </tr>
+ <tr>
+ <td>String</td>
+ <td>108</td>
+ <td>unsupported</td>
+ </tr>
+ <tr>
+ <td>Numeric string</td>
+ <td>109</td>
+ <td>supported</td>
+ </tr>
+ </tbody>
+ </table>
+
+
+ <para>
+ The structure attribute values
+ <literal>Word list (6)</literal>
+ is supported, and maps to the boolean <literal>AND</literal>
+ 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:
+ <screen>
+ Z> find @attr 1=Title @attr 4=6 "mozart amadeus"
+ Z> find @attr 1=Title @and mozart amadeus
+ </screen>
+ </para>
+
+ <para>
+ The structure attribute value
+ <literal>Free-form-text (105)</literal> and
+ <literal>Document-text (106)</literal>
+ are supported, and map both to the boolean <literal>OR</literal>
+ combination of words supplied. The following queries
+ are equivalent:
+ <screen>
+ 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
+ </screen>
+ This <literal>OR</literal> list of terms is very useful in
+ combination with relevance ranking:
+ <screen>
+ Z> find @attr 1=Body-of-text @attr 2=102 @attr 4=105 "bach salieri teleman"
+ </screen>
+ </para>
<para>
- For example, in
+ The structure attribute value
+ <literal>Local number (107)</literal>
+ 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:
+ <screen>
+ Z> find @attr 4=107 10
+ Z> find @attr 1=4 @attr 4=107 10
+ Z> find @attr 1=1010 @attr 4=107 10
+ </screen>
+ </para>
+
+ <para>
+ In
the GILS schema (<literal>gils.abs</literal>), the
west-bounding-coordinate is indexed as type <literal>n</literal>,
and is therefore searched by specifying
Z> find @attr 4=109 @attr 2=5 @attr gils 1=2038 -114
</screen>
</para>
+ <note>
+ The exact mapping between PQF queries and Zebra internal indexes
+ and index types is explained in
+ <xref linkend="querymodel-pqf-apt-mapping"/>.
+ </note>
+
+ </sect3>
<sect3 id="querymodel-bib1-truncation">
<title>Truncation Attributes (type = 5)</title>
+
+ <para>
+ 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.
+ </para>
+
+ <table id="querymodel-bib1-truncation-table"
+ frame="all" rowsep="1" colsep="1" align="center">
+
+ <caption>Truncation Attributes (type 5)</caption>
+ <thead>
+ <tr>
+ <td>Truncation</td>
+ <td>Value</td>
+ <td>Notes</td>
+ </tr>
+ </thead>
+ <tbody>
+ <tr>
+ <td>Right truncation </td>
+ <td>1</td>
+ <td>supported</td>
+ </tr>
+ <tr>
+ <td>Left truncation</td>
+ <td>2</td>
+ <td>supported</td>
+ </tr>
+ <tr>
+ <td>Left and right truncation</td>
+ <td>3</td>
+ <td>supported</td>
+ </tr>
+ <tr>
+ <td>Do not truncate</td>
+ <td>100</td>
+ <td>default</td>
+ </tr>
+ <tr>
+ <td>Process # in search term</td>
+ <td>101</td>
+ <td>supported</td>
+ </tr>
+ <tr>
+ <td>RegExpr-1 </td>
+ <td>102</td>
+ <td>supported</td>
+ </tr>
+ <tr>
+ <td>RegExpr-2</td>
+ <td>103</td>
+ <td>supported</td>
+ </tr>
+ </tbody>
+ </table>
+
+ <para>
+ The truncation attribute values 1-3 perform the obvious way:
+ <screen>
+ 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
+ </screen>
+ </para>
+
+ <para>
+ The truncation attribute value
+ <literal>Process # in search term (101)</literal> is a
+ poor-man's regular expression search. It maps
+ each <literal>#</literal> to <literal>.*</literal>, and
+ performs then a <literal>Regexp-1 (102)</literal> regular
+ expression search. The following two queries are equivalent:
+ <screen>
+ 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
+ </screen>
+ </para>
+
+ <para>
+ The truncation attribute value
+ <literal>Regexp-1 (102)</literal> is a normal regular search,
+ see <xref linkend="querymodel-regular"/> for details.
+ <screen>
+ 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
+ </screen>
+ </para>
+
<para>
- Supported are: No truncation(100) which is the default,
- Right trunation(1), Left truncation(2),
- Left&Right truncation(3),
- Process <literal>#</literal> in term(100) which maps
- each # to <literal>.*</literal>,
- Regexp-1(102) normal regular, Regexp-2(103) (regular with fuzzy),
- <!--
- Special 104, 105, 106 are deprecated and will be removed! -->
+ The truncation attribute value
+ <literal>Regexp-2 (103) </literal> is a Zebra specific extension
+ which allows <emphasis>fuzzy</emphasis> 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.
+ <screen>
+ 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
+ ...
+ </screen>
</para>
</sect3>
<sect3 id="querymodel-bib1-completeness">
<title>Completeness Attributes (type = 6)</title>
+
+
+ <para>
+ The <literal>Completeness Attributes (type = 6)</literal>
+ is used to specify that a given search term or term list is either
+ part of the terms of a given index/field
+ (<literal>Incomplete subfield (1)</literal>), or is
+ what literally is found in the entire field's index
+ (<literal>Complete field (3)</literal>).
+ </para>
+
+ <table id="querymodel-bib1-completeness-table"
+ frame="all" rowsep="1" colsep="1" align="center">
+ <caption>Completeness Attributes (type = 6)</caption>
+ <thead>
+ <tr>
+ <td>Completeness</td>
+ <td>Value</td>
+ <td>Notes</td>
+ </tr>
+ </thead>
+ <tbody>
+ <tr>
+ <td>Incomplete subfield</td>
+ <td>1</td>
+ <td>default</td>
+ </tr>
+ <tr>
+ <td>Complete subfield</td>
+ <td>2</td>
+ <td>depreciated</td>
+ </tr>
+ <tr>
+ <td>Complete field</td>
+ <td>3</td>
+ <td>supported</td>
+ </tr>
+ </tbody>
+ </table>
+
<para>
- 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.
+ The <literal>Completeness Attributes (type = 6)</literal>
+ is only partially and conditionally
+ supported in the sense that it is ignored if the hit index is
+ not of structure <literal>type="w"</literal> or
+ <literal>type="p"</literal>.
+ </para>
+ <para>
+ <literal>Incomplete subfield (1)</literal> is the default, and
+ makes Zebra use
+ register <literal>type="w"</literal>, whereas
+ <literal>Complete field (3)</literal> triggers
+ search and scan in index <literal>type="p"</literal>.
+ </para>
+ <para>
+ The <literal>Complete subfield (2)</literal> is a reminiscens
+ from the happy <literal>MARC</literal>
+ binary format days. Zebra does not support it, but maps silently
+ to <literal>Complete field (3)</literal>.
</para>
+
+ <note>
+ The exact mapping between PQF queries and Zebra internal indexes
+ and index types is explained in
+ <xref linkend="querymodel-pqf-apt-mapping"/>.
+ </note>
</sect3>
</sect2>
+
+ </sect1>
+
+
+ <sect1 id="querymodel-zebra">
+ <title>Advanced Zebra PQF Features</title>
+ <para>
+ The Zebra internal query engine has been extended to specific needs
+ not covered by the <literal>bib-1</literal> attribute set query
+ model. These extensions are <emphasis>non-standard</emphasis>
+ and <emphasis>non-portable</emphasis>: most functional extensions
+ are modeled over the <literal>bib-1</literal> attribute set,
+ defining type 7-9 attributes.
+ There are also the special
+ <literal>string</literal> type index names for the
+ <literal>idxpath</literal> attribute set.
+ </para>
+
+ <sect2 id="querymodel-zebra-attr-allrecords">
+ <title>Zebra specific retrieval of all records</title>
+ <para>
+ Zebra defines a hardwired <literal>string</literal> index name
+ called <literal>_ALLRECORDS</literal>. It matches any record
+ contained in the database, if used in conjunction with
+ the relation attribute
+ <literal>AlwaysMatches (103)</literal>.
+ </para>
+ <para>
+ The <literal>_ALLRECORDS</literal> index name is used for total database
+ export. The search term is ignored, it may be empty.
+ <screen>
+ Z> find @attr 1=_ALLRECORDS @attr 2=103 ""
+ </screen>
+ </para>
+ <para>
+ Combination with other index types can be made. For example, to
+ find all records which are <emphasis>not</emphasis> indexed in
+ the <literal>Title</literal> register, issue one of the two
+ equivalent queries:
+ <screen>
+ 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 ""
+ </screen>
+ </para>
+ <warning>
+ The special string index <literal>_ALLRECORDS</literal> is
+ experimental, and the provided functionality and syntax may very
+ well change in future releases of Zebra.
+ </warning>
+ </sect2>
<sect2 id="querymodel-zebra-attr-search">
- <title>Zebra specific Search Extentions to all Attribute Sets</title>
+ <title>Zebra specific Search Extensions to all Attribute Sets</title>
<para>
- Zebra extends the Bib1 attribute types, and these extentions are
+ Zebra extends the Bib1 attribute types, and these extensions are
recognized regardless of attribute
set used in a <literal>search</literal> operation query.
</para>
- <table id="querymodel-zebra-attr-search-table">
- <caption>Zebra Search Attribute Extentions</caption>
+ <table id="querymodel-zebra-attr-search-table"
+ frame="all" rowsep="1" colsep="1" align="center">
+
+ <caption>Zebra Search Attribute Extensions</caption>
<thead>
<tr>
- <td><emphasis>Name and Type</emphasis></td>
+ <td>Name</td>
+ <td>Value</td>
<td>Operation</td>
<td>Zebra version</td>
</tr>
</thead>
<tbody>
<tr>
- <td><emphasis>Embedded Sort (type 7)</emphasis></td>
+ <td>Embedded Sort</td>
+ <td>7</td>
<td>search</td>
<td>1.1</td>
</tr>
<tr>
- <td><emphasis>Term Set (type 8)</emphasis></td>
+ <td>Term Set</td>
+ <td>8</td>
<td>search</td>
<td>1.1</td>
</tr>
<tr>
- <td><emphasis>Rank weight (type 9)</emphasis></td>
+ <td>Rank Weight</td>
+ <td>9</td>
<td>search</td>
<td>1.1</td>
</tr>
<tr>
- <td><emphasis>Approx Limit (type 9)</emphasis></td>
+ <td>Approx Limit</td>
+ <td>9</td>
<td>search</td>
<td>1.4</td>
</tr>
<tr>
- <td><emphasis>Term Reference (type 10)</emphasis></td>
+ <td>Term Reference</td>
+ <td>10</td>
<td>search</td>
<td>1.4</td>
</tr>
</table>
<sect3 id="querymodel-zebra-attr-sorting">
- <title>Zebra Extention Embedded Sort Attribute (type 7)</title>
+ <title>Zebra Extension Embedded Sort Attribute (type 7)</title>
</sect3>
<para>
The embedded sort is a way to specify sort within a query - thus
faster and does not require clients to deal with the Sort
Facility.
</para>
+
+ <para>
+ All ordering operations are based on a lexicographical ordering,
+ <emphasis>expect</emphasis> when the
+ <literal>structure attribute numeric (109)</literal> is used. In
+ this case, ordering is numerical. See
+ <xref linkend="querymodel-bib1-structure"/>.
+ </para>
+
<para>
The possible values after attribute <literal>type 7</literal> are
<literal>1</literal> ascending and
</para>
<sect3 id="querymodel-zebra-attr-estimation">
- <title>Zebra Extention Term Set Attribute (type 8)</title>
+ <title>Zebra Extension Term Set Attribute (type 8)</title>
</sect3>
<para>
The Term Set feature is a facility that allows a search to store
</warning>
<sect3 id="querymodel-zebra-attr-weight">
- <title>Zebra Extention Rank Weight Attribute (type 9)</title>
+ <title>Zebra Extension Rank Weight Attribute (type 9)</title>
</sect3>
<para>
Rank weight is a way to pass a value to a ranking algorithm - so
</para>
<sect3 id="querymodel-zebra-attr-limit">
- <title>Zebra Extention Approximative Limit Attribute (type 9)</title>
+ <title>Zebra Extension Approximative Limit Attribute (type 9)</title>
</sect3>
<para>
- Newer Zebra versions normally estemiates hit count for every APT
+ Newer Zebra versions normally estimate 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.
reached. A value of zero means exact hit count.
</para>
<para>
- For example, we might be intersted in exact hit count for a, but
+ For example, we might be interested in exact hit count for a, but
for b we allow hit count estimates for 1000 and higher.
<screen>
Z> find @and a @attr 9=1000 b
</screen>
</para>
<note>
- The estimated hit count fascility makes searches faster, as one
+ The estimated hit count facility makes searches faster, as one
only needs to process large hit lists partially.
</note>
<warning>
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.
+ extension. Do not use in production code.
</warning>
<sect3 id="querymodel-zebra-attr-termref">
- <title>Zebra Extention Term Reference Attribute (type 10)</title>
+ <title>Zebra Extension Term Reference Attribute (type 10)</title>
</sect3>
<para>
- Zebra supports the searchResult-1 facility. If attribute 10 is
+ Zebra supports the <literal>searchResult-1</literal> facility.
+ If the <literal>Term Reference Attribute (type 10)</literal> 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.
<sect2 id="querymodel-zebra-attr-scan">
- <title>Zebra specific Scan Extentions to all Attribute Sets</title>
+ <title>Zebra specific Scan Extensions to all Attribute Sets</title>
<para>
- Zebra extends the Bib1 attribute types, and these extentions are
+ Zebra extends the Bib1 attribute types, and these extensions are
recognized regardless of attribute
set used in a <literal>scan</literal> operation query.
</para>
- <table id="querymodel-zebra-attr-scan-table">
- <caption>Zebra Scan Attribute Extentions</caption>
+ <table id="querymodel-zebra-attr-scan-table"
+ frame="all" rowsep="1" colsep="1" align="center">
+
+ <caption>Zebra Scan Attribute Extensions</caption>
<thead>
<tr>
- <td><emphasis>Name and Type</emphasis></td>
+ <td>Name</td>
+ <td>Type</td>
<td>Operation</td>
<td>Zebra version</td>
</tr>
</thead>
<tbody>
<tr>
- <td><emphasis>Result Set Narrow (type 8)</emphasis></td>
+ <td>Result Set Narrow</td>
+ <td>8</td>
<td>scan</td>
<td>1.3</td>
</tr>
<tr>
- <td><emphasis>Approximative Limit (type 9)</emphasis></td>
+ <td>Approximative Limit</td>
+ <td>9</td>
<td>scan</td>
<td>1.4</td>
</tr>
</tbody>
</table>
- <sect3 id="querymodel-zebra-attr-xyz">
- <title>Zebra Extention Result Set Narrow (type 8)</title>
+ <sect3 id="querymodel-zebra-attr-narrow">
+ <title>Zebra Extension Result Set Narrow (type 8)</title>
</sect3>
<para>
- If attribute 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.
+ If attribute <literal>Result Set Narrow (type 8)</literal>
+ is given for <literal>scan</literal>, the value is the name of a
+ result set. Each hit count in <literal>scan</literal> is
+ <literal>@and</literal>'ed with the result set given.
</para>
- <!--
<para>
+ Consider for example
+ the case of scanning all title fields around the
+ scanterm <emphasis>mozart</emphasis>, then refining the scan by
+ issuing a filtering query for <emphasis>amadeus</emphasis> to
+ restrict the scan to the result set of the query:
<screen>
+ 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)
+ ...
</screen>
</para>
- -->
+
<warning>
- Experimental and buggy. Definitely not to be used in production code.
+ Experimental. Do not use in production code.
</warning>
- <sect3 id="querymodel-zebra-attr-xyz">
- <title>Zebra Extention Approximative Limit (type 9)</title>
+ <sect3 id="querymodel-zebra-attr-approx">
+ <title>Zebra Extension Approximative Limit (type 9)</title>
</sect3>
<para>
- The approximative limit (as for search) is a way to enable approx
- hit counts for scan hit counts.
+ The <literal>Zebra Extension Approximative Limit (type
+ 9)</literal> is a way to enable approximate
+ hit counts for <literal>scan</literal> hit counts, in the same
+ way as for <literal>search</literal> hit counts.
</para>
<!--
<para>
</para>
-->
<warning>
- Experimental. Do not use in production code.
+ Experimental and buggy. Definitely not to be used in production code.
</warning>
</sect2>
-
+
+
+ <sect2 id="querymodel-idxpath">
+ <title>Zebra special IDXPATH Attribute Set for GRS indexing</title>
+ <para>
+ The attribute-set <literal>idxpath</literal> consists of a single
+ <literal>Use (type 1)</literal> attribute. All non-use attributes
+ behave as normal.
+ </para>
+ <para>
+ This feature is enabled when defining the
+ <literal>xpath enable</literal> option in the GRS filter
+ <filename>*.abs</filename> configuration files. If one wants to use
+ the special <literal>idxpath</literal> numeric attribute set, the
+ main Zebra configuration file <filename>zebra.cfg</filename>
+ directive <literal>attset: idxpath.att</literal> must be enabled.
+ </para>
+ <warning>The <literal>idxpath</literal> is depreciated, may not be
+ supported in future Zebra versions, and should definitely
+ not be used in production code.
+ </warning>
+
+ <sect3 id="querymodel-idxpath-use">
+ <title>IDXPATH Use Attributes (type = 1)</title>
+ <para>
+ This attribute set allows one to search GRS filter indexed
+ records by XPATH like structured index names.
+ </para>
+
+ <warning>The <literal>idxpath</literal> option defines hard-coded
+ index names, which might clash with your own index names.
+ </warning>
+
+ <table id="querymodel-idxpath-use-table"
+ frame="all" rowsep="1" colsep="1" align="center">
+
+ <caption>Zebra specific IDXPATH Use Attributes (type 1)</caption>
+ <thead>
+ <tr>
+ <td>IDXPATH</td>
+ <td>Value</td>
+ <td>String Index</td>
+ <td>Notes</td>
+ </tr>
+ </thead>
+ <tbody>
+ <tr>
+ <td>XPATH Begin</td>
+ <td>1</td>
+ <td>_XPATH_BEGIN</td>
+ <td>depreciated</td>
+ </tr>
+ <tr>
+ <td>XPATH End</td>
+ <td>2</td>
+ <td>_XPATH_END</td>
+ <td>depreciated</td>
+ </tr>
+ <tr>
+ <td>XPATH CData</td>
+ <td>1016</td>
+ <td>_XPATH_CDATA</td>
+ <td>depreciated</td>
+ </tr>
+ <tr>
+ <td>XPATH Attribute Name</td>
+ <td>3</td>
+ <td>_XPATH_ATTR_NAME</td>
+ <td>depreciated</td>
+ </tr>
+ <tr>
+ <td>XPATH Attribute CData</td>
+ <td>1015</td>
+ <td>_XPATH_ATTR_CDATA</td>
+ <td>depreciated</td>
+ </tr>
+ </tbody>
+ </table>
+
+
+ <para>
+ See <filename>tab/idxpath.att</filename> for more information.
+ </para>
+ <para>
+ Search for all documents starting with root element
+ <literal>/root</literal> (either using the numeric or the string
+ use attributes):
+ <screen>
+ 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/
+ </screen>
+ </para>
+ <para>
+ Search for all documents where specific nested XPATH
+ <literal>/c1/c2/../cn</literal> exists. Notice the very
+ counter-intuitive <emphasis>reverse</emphasis> notation!
+ <screen>
+ 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/
+ </screen>
+ </para>
+ <para>
+ Search for CDATA string <emphasis>text</emphasis> in any element
+ <screen>
+ Z> find @attrset idxpath @attr 1=1016 text
+ Z> find @attr 1=_XPATH_CDATA text
+ </screen>
+ </para>
+ <para>
+ Search for CDATA string <emphasis>anothertext</emphasis> in any
+ attribute:
+ <screen>
+ Z> find @attrset idxpath @attr 1=1015 anothertext
+ Z> find @attr 1=_XPATH_ATTR_CDATA anothertext
+ </screen>
+ </para>
+ <para>
+ Search for all documents with have an XML element node
+ including an XML attribute named <emphasis>creator</emphasis>
+ <screen>
+ Z> find @attrset idxpath @attr 1=3 @attr 4=3 creator
+ Z> find @attr 1=_XPATH_ATTR_NAME @attr 4=3 creator
+ </screen>
+ </para>
+ <para>
+ Combining usual <literal>bib-1</literal> attribute set searches
+ with <literal>idxpath</literal> attribute set searches:
+ <screen>
+ 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
+ </screen>
+ </para>
+ <para>
+ Scanning is supported on all <literal>idxpath</literal>
+ indexes, both specified as numeric use attributes, or as string
+ index names.
+ <screen>
+ 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 ''
+ </screen>
+ </para>
+
+ </sect3>
+ </sect2>
- <sect2 id="querymodel-bib1-mapping">
- <title>Mapping from Bib1 Attributes to Zebra internal
+
+ <sect2 id="querymodel-pqf-apt-mapping">
+ <title>Mapping from PQF atomic APT queries to Zebra internal
register indexes</title>
<para>
- TO-DO
- </para>
-
-
- <!-- see in util/zebramap.c
- int zebra_maps_attr
-
- if (completeness_value == 2 || completeness_value == 3)
- *complete_flag = 1;
- else
- *complete_flag = 0;
- *reg_id = 0;
-
- *sort_flag =(sort_relation_value > 0) ? 1 : 0;
- *search_type = "phrase";
- strcpy(rank_type, "void");
- if (relation_value == 102)
- {
- if (weight_value == -1)
- weight_value = 34;
- sprintf(rank_type, "rank,w=%d,u=%d", weight_value, use_value);
- }
- if (relation_value == 103)
- {
- *search_type = "always";
- *reg_id = 'w';
- return 0;
- }
- if (*complete_flag)
- *reg_id = 'p';
- else
- *reg_id = 'w';
- switch (structure_value)
- {
- case 6: /* word list */
- *search_type = "and-list";
- break;
- case 105: /* free-form-text */
- *search_type = "or-list";
- break;
- case 106: /* document-text */
- *search_type = "or-list";
- break;
- case -1:
- case 1: /* phrase */
- case 2: /* word */
- case 108: /* string */
- *search_type = "phrase";
- break;
- case 107: /* local-number */
- *search_type = "local";
- *reg_id = 0;
- break;
- case 109: /* numeric string */
- *reg_id = 'n';
- *search_type = "numeric";
- break;
- case 104: /* urx */
- *reg_id = 'u';
- *search_type = "phrase";
- break;
- case 3: /* key */
- *reg_id = '0';
- *search_type = "phrase";
- break;
- case 4: /* year */
- *reg_id = 'y';
- *search_type = "phrase";
- break;
- case 5: /* date */
- *reg_id = 'd';
- *search_type = "phrase";
- break;
- default:
- return -1;
- }
- return 0;
-
- -->
+ 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.
+ </para>
-
+ <sect3 id="querymodel-pqf-apt-mapping-accesspoint">
+ <title>Mapping of PQF APT access points</title>
<para>
- <emphasis>Use</emphasis> attributes are interpreted according to the
- attribute sets which have been loaded in the
- <literal>zebra.cfg</literal> file, and are matched against specific
- fields as specified in the <literal>.abs</literal> 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.
+ Zebra understands four fundamental different types of access
+ points, of which only the
+ <emphasis>numeric use attribute</emphasis> type access points
+ are defined by the <ulink url="&url.z39.50;">Z39.50</ulink>
+ standard.
+ All other access point types are Zebra specific, and non-portable.
</para>
-
+
+ <table id="querymodel-zebra-mapping-accesspoint-types"
+ frame="all" rowsep="1" colsep="1" align="center">
+
+ <caption>Access point name mapping</caption>
+ <thead>
+ <tr>
+ <td>Access Point</td>
+ <td>Type</td>
+ <td>Grammar</td>
+ <td>Notes</td>
+ </tr>
+ </thead>
+ <tbody>
+ <tr>
+ <td>Use attribute</td>
+ <td>numeric</td>
+ <td>[1-9][1-9]*</td>
+ <td>directly mapped to string index name</td>
+ </tr>
+ <tr>
+ <td>String index name</td>
+ <td>string</td>
+ <td>[a-zA-Z](\-?[a-zA-Z0-9])*</td>
+ <td>normalized name is used as internal string index name</td>
+ </tr>
+ <tr>
+ <td>Zebra internal index name</td>
+ <td>zebra</td>
+ <td>_[a-zA-Z](_?[a-zA-Z0-9])*</td>
+ <td>hardwired internal string index name</td>
+ </tr>
+ <tr>
+ <td>XPATH special index</td>
+ <td>XPath</td>
+ <td>/.*</td>
+ <td>special xpath search for GRS indexed records</td>
+ </tr>
+ </tbody>
+ </table>
+
+ <para>
+ <literal>Attribute set names</literal> and
+ <literal>string index names</literal> are normalizes
+ according to the following rules: all <emphasis>single</emphasis>
+ hyphens <literal>'-'</literal> are stripped, and all upper case
+ letters are folded to lower case.
+ </para>
+
+ <para>
+ <emphasis>Numeric use attributes</emphasis> are mapped
+ to the Zebra internal
+ string index according to the attribute set definition in use.
+ The default attribute set is <literal>Bib-1</literal>, and may be
+ omitted in the PQF query.
+ </para>
+
+ <para>
+ 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):
+ <screen>
+ 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
+ </screen>
+ </para>
+
+ <para>
+ The <emphasis>numerical</emphasis>
+ <literal>use attributes (type 1)</literal>
+ are interpreted according to the
+ attribute sets which have been loaded in the
+ <literal>zebra.cfg</literal> file, and are matched against specific
+ fields as specified in the <literal>.abs</literal> file which
+ describes the profile of the records which have been loaded.
+ If no use attribute is provided, a default of
+ <literal>Bib-1 Use Any (1016)</literal> is
+ assumed.
+ The predefined <literal>use attribute sets</literal>
+ can be reconfigured by tweaking the configuration files
+ <filename>tab/*.att</filename>, and
+ new attribute sets can be defined by adding similar files in the
+ configuration path <literal>profilePath</literal> of the server.
+ </para>
+
+ <para>
+ <literal>String indexes</literal> can be accessed directly,
+ independently which attribute set is in use. These are just
+ ignored. The above mentioned name normalization applies.
+ <literal>String index names</literal> are defined in the
+ used indexing filter configuration files, for example in the
+ <literal>GRS</literal>
+ <filename>*.abs</filename> configuration files, or in the
+ <literal>alvis</literal> filter XSLT indexing stylesheets.
+ </para>
+
+ <para>
+ <literal>Zebra internal indexes</literal> can be accessed directly,
+ according to the same rules as the user defined
+ <literal>string indexes</literal>. The only difference is that
+ <literal>Zebra internal index names</literal> are hardwired,
+ all uppercase and
+ must start with the character <literal>'_'</literal>.
+ </para>
+
+ <para>
+ Finally, <literal>XPATH</literal> access points are only
+ available using the <literal>GRS</literal> filter for indexing.
+ These access point names must start with the character
+ <literal>'/'</literal>, they are <emphasis>not
+ normalized</emphasis>, but passed unaltered to the Zebra internal
+ XPATH engine. See <xref linkend="querymodel-use-xpath"/>.
+
+ </para>
+
+
+ </sect3>
+
+
+ <sect3 id="querymodel-pqf-apt-mapping-structuretype">
+ <title>Mapping of PQF APT structure and completeness to
+ register type</title>
+ <para>
+ 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 rulesets.
+ </para>
+
+ <table id="querymodel-zebra-mapping-structure-types"
+ frame="all" rowsep="1" colsep="1" align="center">
+
+ <caption>Structure and completeness mapping to register types</caption>
+ <thead>
+ <tr>
+ <td>Structure</td>
+ <td>Completeness</td>
+ <td>Register type</td>
+ <td>Notes</td>
+ </tr>
+ </thead>
+ <tbody>
+ <tr>
+ <td>
+ 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)
+ </td>
+ <td>Incomplete field (@attr 6=1)</td>
+ <td>Word ('w')</td>
+ <td>Traditional tokenized and character normalized word index</td>
+ </tr>
+ <tr>
+ <td>
+ 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)
+ </td>
+ <td>complete field' (@attr 6=3)</td>
+ <td>Phrase ('p')</td>
+ <td>Character normalized, but not tokenized index for phrase
+ matches
+ </td>
+ </tr>
+ <tr>
+ <td>urx (@attr 4=104)</td>
+ <td>ignored</td>
+ <td>URX/URL ('u')</td>
+ <td>Special index for URL web adresses</td>
+ </tr>
+ <tr>
+ <td>numeric (@attr 4=109)</td>
+ <td>ignored</td>
+ <td>Numeric ('u')</td>
+ <td>Special index for digital numbers</td>
+ </tr>
+ <tr>
+ <td>key (@attr 4=3)</td>
+ <td>ignored</td>
+ <td>Null bitmap ('0')</td>
+ <td>Used for non-tokenizated and non-normalized bit sequences</td>
+ </tr>
+ <tr>
+ <td>year (@attr 4=4)</td>
+ <td>ignored</td>
+ <td>Year ('y')</td>
+ <td>Non-tokenizated and non-normalized 4 digit numbers</td>
+ </tr>
+ <tr>
+ <td>date (@attr 4=5)</td>
+ <td>ignored</td>
+ <td>Date ('d')</td>
+ <td>Non-tokenizated and non-normalized ISO date strings</td>
+ </tr>
+ <tr>
+ <td>ignored</td>
+ <td>ignored</td>
+ <td>Sort ('s')</td>
+ <td>Used with special sort attribute set (@attr 7=1, @attr 7=2)</td>
+ </tr>
+ <tr>
+ <td>overruled</td>
+ <td>overruled</td>
+ <td>special</td>
+ <td>Internal record ID register, used whenever
+ Relation Always Matches (@attr 2=103) is specified</td>
+ </tr>
+ </tbody>
+ </table>
+
+ <!-- see in util/zebramap.c -->
+
<para>
If a <emphasis>Structure</emphasis> attribute of
<emphasis>Phrase</emphasis> is used in conjunction with a
against the contents of the phrase (long word) register, if one
exists for the given <emphasis>Use</emphasis> attribute.
A phrase register is created for those fields in the
- <literal>.abs</literal> file that contains a
+ GRS <filename>*.abs</filename> file that contains a
<literal>p</literal>-specifier.
- <!-- ### whatever the hell _that_ is -->
+ <screen>
+ 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
+ </screen>
</para>
<para>
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 <literal>w</literal> in the <literal>.abs</literal> file.
+ type <literal>w</literal> in the GRS <filename>*.abs</filename> file.
+ <screen>
+ 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
+ ...
+ </screen>
</para>
<para>
natural-language, relevance-ranked query.
This search type uses the word register, i.e. those fields
that are indexed as type <literal>w</literal> in the
- <literal>.abs</literal> file.
+ GRS <filename>*.abs</filename> file.
</para>
<para>
If the <emphasis>Structure</emphasis> attribute is
<emphasis>Numeric String</emphasis> the term is treated as an integer.
The search is performed on those fields that are indexed
- as type <literal>n</literal> in the <literal>.abs</literal> file.
+ as type <literal>n</literal> in the GRS
+ <filename>*.abs</filename> file.
</para>
<para>
If the <emphasis>Structure</emphasis> attribute is
- <emphasis>URx</emphasis> the term is treated as a URX (URL) entity.
+ <emphasis>URX</emphasis> the term is treated as a URX (URL) entity.
The search is performed on those fields that are indexed as type
- <literal>u</literal> in the <literal>.abs</literal> file.
+ <literal>u</literal> in the <filename>*.abs</filename> file.
</para>
<para>
replacement) is accepted when terms are matched against the register
contents.
</para>
+
+ </sect3>
</sect2>
<sect2 id="querymodel-regular">
Both query types follow the same syntax with the operands:
</para>
- <table id="querymodel-regular-operands-table">
+ <table id="querymodel-regular-operands-table"
+ frame="all" rowsep="1" colsep="1" align="center">
+
<caption>Regular Expression Operands</caption>
<!--
<thead>
-->
<tbody>
<tr>
- <td><emphasis>x</emphasis></td>
- <td>Matches the character <emphasis>x</emphasis>.</td>
+ <td><literal>x</literal></td>
+ <td>Matches the character <literal>x</literal>.</td>
</tr>
<tr>
- <td><emphasis>.</emphasis></td>
+ <td><literal>.</literal></td>
<td>Matches any character.</td>
</tr>
<tr>
- <td><emphasis>[ .. ]</emphasis></td>
+ <td><literal>[ .. ]</literal></td>
<td>Matches the set of characters specified;
such as <literal>[abc]</literal> or <literal>[a-c]</literal>.</td>
</tr>
The above operands can be combined with the following operators:
</para>
-
- <table id="querymodel-regular-operators-table">
+ <table id="querymodel-regular-operators-table"
+ frame="all" rowsep="1" colsep="1" align="center">
<caption>Regular Expression Operators</caption>
<!--
<thead>
-->
<tbody>
<tr>
- <td><emphasis>x*</emphasis></td>
- <td>Matches <emphasis>x</emphasis> zero or more times.
+ <td><literal>x*</literal></td>
+ <td>Matches <literal>x</literal> zero or more times.
Priority: high.</td>
</tr>
<tr>
- <td><emphasis>x+</emphasis></td>
- <td>Matches <emphasis>x</emphasis> one or more times.
+ <td><literal>x+</literal></td>
+ <td>Matches <literal>x</literal> one or more times.
Priority: high.</td>
</tr>
<tr>
- <td><emphasis>x?</emphasis></td>
- <td> Matches <emphasis>x</emphasis> zero or once.
+ <td><literal>x?</literal></td>
+ <td> Matches <literal>x</literal> zero or once.
Priority: high.</td>
</tr>
<tr>
- <td><emphasis>xy</emphasis></td>
- <td> Matches <emphasis>x</emphasis>, then <emphasis>y</emphasis>.
+ <td><literal>xy</literal></td>
+ <td> Matches <literal>x</literal>, then <literal>y</literal>.
Priority: medium.</td>
</tr>
<tr>
- <td><emphasis>x|y</emphasis></td>
- <td> Matches either <emphasis>x</emphasis> or <emphasis>y</emphasis>.
+ <td><literal>x|y</literal></td>
+ <td> Matches either <literal>x</literal> or <literal>y</literal>.
Priority: low.</td>
</tr>
<tr>
- <td><emphasis>( )</emphasis></td>
+ <td><literal>( )</literal></td>
<td>The order of evaluation may be changed by using parentheses.</td>
</tr>
</tbody>
</table>
-
+
<para>
- If the first character of the <emphasis>Regxp-2</emphasis> query
+ If the first character of the <literal>Regxp-2</literal> query
is a plus character (<literal>+</literal>) it marks the
beginning of a section with non-standard specifiers.
The next plus character marks the end of the section.
<para>
Combinations with other attributes are possible. For example, a
- ranked search with a regular expression
- (see <xref linkend="administration-ranking"/> for the glory details):
+ ranked search with a regular expression:
<screen>
Z> find @attr 1=4 @attr 5=102 @attr 2=102 "informat.* retrieval"
</screen>
process input records.
Two basic types of processing are available - raw text and structured
data. Raw text is just that, and it is selected by providing the
- argument <emphasis>text</emphasis> to Zebra. Structured records are
+ argument <literal>text</literal> to Zebra. Structured records are
all handled internally using the basic mechanisms described in the
subsequent sections.
Zebra can read structured records in many different formats.
projects / idzebra-moved-to-github.git / blobdiff