You only need apply it in the index analyzer:
https://lucene.apache.org/solr/8_4_0/solr-core/org/apache/solr/analysis/ReversedWildcardFilterFactory.html
If it appears in the index analyzer, the query part of it is automatically
applied at query time.
The ReversedWildcardFilter indexes *every* token in reverse, with a special
character at the start ('\u0001' I believe) to avoid false positive matches
when the query term isn't reversed (e.g. if the term being indexed is mar,
then the reversed token would be \u0001ram, so a search for 'ram' wouldn't
accidentally match that). If *withOriginal* is set to true then it will
reverse the normal token as well as the reversed token.
On Thu, 9 Apr 2020 at 02:27, TK Solr <tksol...@sonic.net> wrote:
> I experimented with the index-time only use of ReversedWildcardFilter and
> the
> both time use.
>
> My result shows using ReverseWildcardFilter both times runs twice as fast
> but my
> dataset is not very large (in the order of 10k docs), so I'm not sure if I
> can
> make a conclusion.
>
> On 4/8/20 2:49 PM, TK Solr wrote:
> > In the usage example shown in ReversedWildcardFilter
> > <
> https://lucene.apache.org/solr/guide/8_3/filter-descriptions.html#reversed-wildcard-filter>
>
> > in Solr Ref Guide,
> > and only usage find in managed-schema to define text_general_rev, the
> filter
> > is used only for indexing.
> >
> > <fieldType name="text_general_rev" class="solr.TextField"
> > positionIncrementGap="100">
> > <analyzer type="index">
> > <tokenizer class="solr.StandardTokenizerFactory"/>
> > <filter class="solr.StopFilterFactory" words="stopwords.txt"
> > ignoreCase="true"/>
> > <filter class="solr.LowerCaseFilterFactory"/>
> > <filter class="solr.ReversedWildcardFilterFactory"
> maxPosQuestion="2"
> > maxFractionAsterisk="0.33" maxPosAsterisk="3" withOriginal="true"/>
> > </analyzer>
> > <analyzer type="query">
> > <tokenizer class="solr.StandardTokenizerFactory"/>
> > <filter class="solr.SynonymGraphFilterFactory" expand="true"
> > ignoreCase="true" synonyms="synonyms.txt"/>
> > <filter class="solr.StopFilterFactory" words="stopwords.txt"
> > ignoreCase="true"/>
> > <filter class="solr.LowerCaseFilterFactory"/>
> > </analyzer>
> > </fieldType>
> >
> >
> > Is it incorrect to use the same analyzer for query like?
> >
> > <fieldType name="lowercase_rev" class="solr.TextField"
> > positionIncrementGap="100">
> > <!-- Added to handle right-anchored substring match for email fields
> -->
> > <analyzer>
> > <tokenizer class="solr.WhitespaceTokenizerFactory"/>
> > <filter class="solr.LowerCaseFilterFactory"/>
> > <filter class="solr.ReversedWildcardFilterFactory"
> maxPosQuestion="0"
> > maxFractionAsterisk="0" maxPosAsterisk="100" withOriginal="false"/>
> > </analyzer>
> > </fieldType>
> >
> > In the description of filter, I see "Tokens without wildcards are not
> reversed."
> > But the wildcard appears only in the query string. How can
> > ReversedWildcardFilter know if the wildcard is being used
> > if the filter is used only at the indexing time?
> >
> > TK
> >
> >
>
