Specifies that this element is to be used to
help rank
records against the user's query (when ranking is
- requested). The value is an integer, used as a
- multiplier against the basic TF*IDF score. A value of
- 1 is the base, higher values give additional
- weight to
+ requested).
+ The valus is of the form
+ <literallayout>
+ M [F N]
+ </literallayout>
+ where M is an integer, used as a
+ weight against the basic TF*IDF score. A value of
+ 1 is the base, higher values give additional weight to
elements of this type. The default is '0', which
excludes this element from the rank calculation.
</para>
<para>
+ F is a CCL field and N is the multipler for terms
+ that matches those part of the CCL field in search.
+ The F+N combo allows the system to use a different
+ multipler for a certain field. For example, a rank value of
+ "<literal>1 au 3</literal>" gives a multipler of 3 for
+ all terms part of the au(thor) terms and 1 for everything else.
+ </para>
+ <para>
For Pazpar2 1.6.13 and later, the rank may also defined
"per-document", by the normalization stylesheet.
</para>
+ <para>
+ The per field rank was introduced in Pazpar2 1.6.15. Earlier
+ releases only allowed a rank value M (simple integer).
+ </para>
+ See <xref linkend="relevance_ranking"/> for more
+ about ranking.
</listitem>
</varlistentry>
all elements), or 'no' (don't merge; this is the
default);
</para>
+ <para>
+ Pazpar 1.6.24 also offers a new value for merge, 'first', which
+ is like 'all' but only takes all from first database that returns
+ the particular metadata field.
+ </para>
</listitem>
</varlistentry>
</varlistentry>
<varlistentry>
+ <term id="limitcluster">limitcluster</term>
+ <listitem>
+ <para>
+ Allow a limit on merged metadata. The value of this attribute
+ is the name of actual metadata content to be used for matching
+ (most often same name as metadata name).
+ </para>
+ <note>
+ <para>
+ Requires Pazpar2 1.6.23 or later.
+ </para>
+ </note>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
<term id="metadata_limitmap">limitmap</term>
<listitem>
<para>
</para>
</listitem>
</varlistentry>
+
+ <varlistentry>
+ <term>ccldirective</term>
+ <listitem>
+ <para>
+ Customizes the CCL parsing (interpretation of query parameter
+ in search).
+ The name and value of the CCL directive is gigen by attributes
+ 'name' and 'value' respectively. Refer to possible list of names
+ in the
+ <ulink
+ url="http://www.indexdata.com/yaz/doc/tools.html#ccl.directives.table">
+ YAZ manual
+ </ulink>.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term>rank</term>
+ <listitem>
+ <para>
+ Customizes the ranking (relevance) algorithm. Also known as
+ rank tweaks. The rank element
+ accepts the following attributes - all being optional:
+ </para>
+ <variablelist>
+ <varlistentry>
+ <term>cluster</term>
+ <listitem>
+ <para>
+ Attribute 'cluster' is a boolean
+ that controls whether Pazpar2 should boost ranking for merged
+ records. Is 'yes' by default. A value of 'no' will make
+ Pazpar2 average ranking of each record in a cluster.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>debug</term>
+ <listitem>
+ <para>
+ Attribute 'debug' is a boolean
+ that controls whether Pazpar2 should include details
+ about ranking for each document in the show command's
+ response. Enable by using value "yes", disable by using
+ value "no" (default).
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>follow</term>
+ <listitem>
+ <para>
+ Attribute 'follow' is a a floating point number greater than
+ or equal to 0. A positive number will boost weight for terms
+ that occur close to each other (proximity, distance).
+ A value of 1, will double the weight if two terms are in
+ proximity distance of 1 (next to each other). The default
+ value of 'follow' is 0 (order will not affect weight).
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>lead</term>
+ <listitem>
+ <para>
+ Attribute 'lead' is a floating point number.
+ It controls if term weight should be reduced by position
+ from start in a metadata field. A positive value of 'lead'
+ will reduce weight as it apperas further away from the lead
+ of the field. Default value is 0 (no reduction of weight by
+ position).
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>length</term>
+ <listitem>
+ <para>
+ Attribute 'length' determines how/if term weight should be
+ divided by lenght of metadata field. A value of "linear"
+ divide by length. A value of "log" will divide by log2(length).
+ A value of "none" will leave term weight as is (no division).
+ Default value is "linear".
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ <para>
+ Refer to <xref linkend="relevance_ranking"/> to see how
+ these tweaks are used in computation of score.
+ </para>
+ <para>
+ Customization of ranking algorithm was introduced with
+ Pazpar2 1.6.18. The semantics of some of the fields changed
+ in versions up to 1.6.22.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry id="sort-default">
+ <term>sort-default</term>
+ <listitem>
+ <para>
+ Specifies the default sort criteria (default 'relevance'),
+ which previous was hard-coded as default criteria in search.
+ This is a fix/work-around to avoid re-searching when using
+ target-based sorting. In order for this to work efficient,
+ the search must also have the sort critera parameter; otherwise
+ pazpar2 will do re-searching on search criteria changes, if
+ changed between search and show command.
+ </para>
+ <para>
+ This configuration was added in pazpar2 1.6.20.
+ </para>
+ </listitem>
+ </varlistentry>
+
+<!--
<varlistentry>
<term>set</term>
<listitem>
</para>
</listitem>
</varlistentry>
-
+-->
<varlistentry>
<term>settings</term>
<listitem>
</listitem>
</varlistentry>
<varlistentry>
+ <term>pz:extendrecs</term>
+ <listitem>
+ <para>
+ If a show command goes to the boundary of a result set for a
+ database - depends on sorting - and pz:extendrecs is set to a larger
+ value of pz:maxrecs, then Pazpar2 wait for show to fetch remaining
+ records - up to pz:extendrecs. This setting is best used if a
+ database does native sorting, because the result set otherwise may
+ be completely re-sorted during extended fetch.
+ </para>
+ <note>
+ <para>
+ The pz:extendrecs setting is supported in Pazpar2 version 1.6.26.
+ </para>
+ </note>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
<term>pz:presentchunk</term>
<listitem>
<para>
by a field a metadata field (default is to use the name of the
limitmap itself).
</para>
+ <para>
+ For Pazpar2 version 1.6.23 and later the limitmap may include multiple
+ specifications, separated by <literal>,</literal> (comma).
+ For example:
+ <literal>ccl:title,local:ltitle,rpn:@attr 1=4</literal>.
+ </para>
<note>
<para>
The limitmap facility is supported for Pazpar2 version 1.6.0.
projects / pazpar2-moved-to-github.git / blobdiff