The lucene based query handler implementation supports a pluggable spell checker mechanism. By default, spell checking is not available and you have to configure it first. See parameter spellCheckerClass on page Search Configuration. JCR currently provides an implementation class , which uses the lucene-spellchecker to contribute . The dictionary is derived from the fulltext indexed content of the workspace and updated periodically. You can configure the refresh interval by picking one of the available inner classes of org.exoplatform.services.jcr.impl.core.query.lucene.spell.LuceneSpellChecker:

For example, if you want a refresh interval of six hours, the class name is: org.exoplatform.services.jcr.impl.core.query.lucene.spell.LuceneSpellChecker$SixHoursRefreshInterval. If you use org.exoplatform.services.jcr.impl.core.query.lucene.spell.LuceneSpellChecker, the refresh interval will be one hour.

The spell checker dictionary is stored as a lucene index under "index-dir"/spellchecker. If it does not exist, a background thread will create it on startup. Similarly, the dictionary refresh is also done in a background thread to not block regular queries.