<chapter id="querymodel">
- <!-- $Id: querymodel.xml,v 1.11 2006-06-22 14:01:55 marc Exp $ -->
+ <!-- $Id: querymodel.xml,v 1.12 2006-06-23 11:12:07 marc Exp $ -->
<title>Query Model</title>
<sect1 id="querymodel-overview">
<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
</sect3>
<para>
- The use attributes (type 1) of the predefined attribute sets can
- be reconfigured by tweaking the files
- <filename>tab/*.att</filename>.
- New attribute sets can be defined by adding similar files in the
- configuration path of the server.
+ 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>
default index using the default attribite 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 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>
<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
</screen>
</para>
<para>
- See also <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
debugging facility.
</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
<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
<tr>
<td>AlwaysMatches</td>
<td>103</td>
- <td>unsupported</td>
+ <td>supported</td>
</tr>
</tbody>
</table>
<para>
The relation attribute
- <literal>relevance (102)</literal> is supported, see
+ <literal>Relevance (102)</literal> is supported, see
<xref linkend="administration-ranking"/> for full information.
- <!-- always-matches (103) not supported for all indexes -->
</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>
+ 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>
- Ranked search for <emphasis>information retrieval</emphasis> in
- the title-register:
- <screen>
- Z> find @attr 1=4 @attr 2=102 "information retrieval"
- </screen>
- </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>
+
+
</sect3>
<sect3 id="querymodel-bib1-position">
<note>
The exact mapping between PQF queries and Zebra internal indexes
and index types is explained in
- <xref linkend="querymodel-bib1-mapping"/>.
+ <xref linkend="querymodel-pqf-apt-mapping"/>.
</note>
</sect3>
<note>
The exact mapping between PQF queries and Zebra internal indexes
and index types is explained in
- <xref linkend="querymodel-bib1-mapping"/>.
+ <xref linkend="querymodel-pqf-apt-mapping"/>.
</note>
</sect3>
</sect2>
<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>
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
</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
+ 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 tetermining 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>
+ 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>Acces point name</caption>
+ <thead>
+ <tr>
+ <td>Acess Point</td>
+ <td>Type</td>
+ <td>Grammar</td>
+ <td>Notes</td>
+ </tr>
+ </thead>
+ <tbody>
+ <tr>
+ <td>Use attibute</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 defintion in use.
+ The default attribute set is <literal>Bib-1</literal>, and may be
+ omitted in the PQF query. According to normalization and numeric
+ use attribute mapping, it follows that the following
+ PQF queries are considered equivalent (assuming the default
+ configuration has not been altered):
+ <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 Bib-1 Any 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 acessed 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 acessed directly,
+ according to the same rules as the user defined
+ <literal>string indexes</literal>. The only difference is that
+ <literal>Zebra internal indexe 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 acees 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 type</title>
+ <para>
+
+ </para>
<!-- see in util/zebramap.c
int zebra_maps_attr
-->
- <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.
- </para>
<para>
If a <emphasis>Structure</emphasis> attribute of
replacement) is accepted when terms are matched against the register
contents.
</para>
+
+ </sect3>
</sect2>
<sect2 id="querymodel-regular">
projects / idzebra-moved-to-github.git / commitdiff