Query Elevation Component
The Query Elevation Component lets you configure the top results for a given query regardless of the normal Lucene scoring.
This is sometimes called "sponsored search", "editorial boosting", or "best bets." This component matches the user query text to a configured map of top results. The text can be any string or non-string IDs, as long as it’s indexed. Although this component will work with any QueryParser, it makes the most sense to use with the DisMax Query Parser or the Extended DisMax (eDisMax) Query Parser.
The Query Elevation Component also supports distributed searching.
All of the sample configuration and queries used in this section assume you are running Solr’s "techproducts" example:
bin/solr -e techproducts
You can configure the Query Elevation Component in the
Search components like
QueryElevationComponent may be added to any request handler; a dedicated request handler is used here for brevity.
<searchComponent name="elevator" class="solr.QueryElevationComponent" > <!-- pick a fieldType to analyze queries --> <str name="queryFieldType">string</str> <str name="config-file">elevate.xml</str> </searchComponent> <requestHandler name="/elevate" class="solr.SearchHandler" startup="lazy"> <lst name="defaults"> <str name="echoParams">explicit</str> </lst> <arr name="last-components"> <str>elevator</str> </arr> </requestHandler>
Optionally, in the Query Elevation Component configuration you can also specify the following to distinguish editorial results from "normal" results:
The Query Elevation search component takes the following parameters:
Specifies which field type should be used to analyze the incoming text. For example, it may be appropriate to use a field type with a
Another example is if you need to unescape backslash-escaped queries, then you can define the field type to preprocess with a
PatternReplaceCharFilter. Here is the corresponding example of a field type:
<fieldType name="unescapelowercase" class="solr.TextField"> <analyzer> <charFilter class="solr.PatternReplaceCharFilterFactory" pattern="\\(.)" replacement="$1"/> <tokenizer class="solr.StandardTokenizerFactory"/> <filter class="solr.LowerCaseFilterFactory"/> </analyzer> </fieldType>
For example, to unescape only non-alphanumeric, the pattern could be
Path to the file that defines the elevation rules. This file must exist in the configset. Unlike most configuration, this component will re-read its configuration if the file changed following a commit. However, that doesn’t work in SolrCloud, and there has to be an actual index change for a commit to have an effect for it to be used as a way to pick up changes. In all cases, you can reload affected cores/collections to use any new configuration in a configset.
By default, this component respects the requested
sortparameter: if the request asks to sort by date, it will order the results by date. If
forceElevation=true, results will first return the boosted docs, then order by date. This defaults to
false. This is also a request parameter, which will override the config.
When multiple docs are elevated, should their relative order be the order in the configuration file or should they be subject to whatever the sort criteria is? This is also a request parameter, which will override the config. The effect is most apparent when
forceElevationis true and there is sorting on fields.
By default, the component will also elevate docs that aren’t part of the search result (matching the query). If you only want to elevate the docs that are part of the search result, set this to
Elevated query results can be configured in an external XML file specified in the
elevate.xml file might look like this:
<elevate> <query text="foo bar"> <doc id="1" /> <doc id="2" /> <doc id="3" /> </query> <query text="ipod"> <doc id="MA147LL/A" /> <!-- put the actual ipod at the top --> <doc id="IW-02" exclude="true" /> <!-- exclude this cable --> </query> <query text="foo bill" match="subset"> <doc id="11" /> </query> </elevate>
In this example, the query "foo bar" would first return documents 1, 2 and 3, then whatever normally appears for the same query. For the query "ipod", it would first return "MA147LL/A", and would make sure that "IW-02" is not in the result set.
match parameter with the value
"subset" for the third rule.
A query "bill bar foo" would trigger this rule because the rule defines a subset of terms to appear in the query, in any order.
This query would elevate document 11 on top.
match parameter accepts either
"exact" (by default) or
Subset matching is scalable, one can add many rules with the
If documents to be elevated are not defined in the
elevate.xml file, they should be passed in at query time with the
For debugging it may be useful to see results with and without the elevated docs.
To hide results, use
You can force elevation during runtime by adding
forceElevation=true to the query URL:
You can force Solr to return only the results specified in the elevation file by adding
exclusive=true to the URL:
You can force set
useConfiguredElevatedOrder during runtime by supplying it as a request parameter.
[elevated] Document Transformer can be used to annotate each document with information about whether or not it was elevated:
Likewise, it can be helpful when troubleshooting to see all matching documents – including documents that the elevation configuration would normally exclude.
This is possible by using the
markExcludes=true parameter, and then using the
When the elevation component is in use, the pre-configured list of elevations for a query can be overridden at request time to use the unique keys specified in these request parameters.
For example, in the request below documents 3007WFP and 9885A004 will be elevated, and document IW-02 will be excluded — regardless of what elevations or exclusions are configured for the query "cable" in elevate.xml:
If either one of these parameters is specified at request time, the entire elevation configuration for the query is ignored.
For example, in the request below documents IW-02 and F8V7067-APL-KIT will be elevated, and no documents will be excluded – regardless of what elevations or exclusions are configured for the query "ipod" in elevate.xml: