Apache Solr Reference Guide Covering Apache Solr 6.0

solr.IndexBasedSpellChecker
./spellchecker
content
true
The first element defines the searchComponent to use the solr.SpellCheckComponent. The classname i
s the specific implementation of the SpellCheckComponent, in this case solr.IndexBasedSpellChecker.
Defining the classname is optional; if not defined, it will default to IndexBasedSpellChecker.
The spellcheckIndexDir defines the location of the directory that holds the spellcheck index, while the fiel
d defines the source field (defined in the Schema) for spell check terms. When choosing a field for the spellcheck
index, it's best to avoid a heavily processed field to get more accurate results. If the field has many word
variations from processing synonyms and/or stemming, the dictionary will be created with those variations in
addition to more valid spelling data.
Finally, buildOnCommit defines whether to build the spell check index at every commit (that is, every time new
documents are added to the index). It is optional, and can be omitted if you would rather set it to false.
DirectSolrSpellChecker
The DirectSolrSpellChecker uses terms from the Solr index without building a parallel index like the Index
BasedSpellChecker. This spell checker has the benefit of not having to be built regularly, meaning that the
terms are always up-to-date with terms in the index. Here is how this might be configured in solrconfig.xml
default
name
solr.DirectSolrSpellChecker
internal
0.5
2
1
5
4
0.01
.01
When choosing a field to query for this spell checker, you want one which has relatively little analysis
performed on it (particularly analysis such as stemming). Note that you need to specify a field to use for the
suggestions, so like the IndexBasedSpellChecker, you may want to copy data from fields like title, body,
etc., to a field dedicated to providing spelling suggestions.
Many of the parameters relate to how this spell checker should query the index for term suggestions. The dista
nceMeasure defines the metric to use during the spell check query. The value "internal" uses the default
Apache Solr Reference Guide 6.0
324