fts-Lucene plugin

fts-lucene-plugin

fts_lucene

Example config to use full-text search with Lucene’s C++ library:

mail_plugins = $mail_plugins fts fts_lucene

plugin {
  fts = lucene
  fts_lucene = whitespace_chars=@.
}

fts_lucene supports the following options:

  • whitespace_chars=<chars>: List of characters that are translated to whitespace. You may want to use “@.” so that e.g. in “first.last@example.org” it won’t be treated as a single word, but rather you can search separately for “first”, “last” and “example”.

  • default_language=<lang>: Default stemming language to use for mails. The default is english. Requires that Dovecot is built with libstemmer, which also limits the languages that are supported.

  • textcat_conf=<path>, textcat_dir=<path>: If specified, enable guessing the stemming language for emails and search keywords. This is a little bit problematic in practice, since indexing and searching languages may differ and may not find even exact words because they stem differently.

  • no_snowball: Support normalization of indexed words even without stemming and libstemmer (Snowball).

  • mime_parts: Index each MIME part separately and include the MIME part number in the “part” field. In future versions this will allowing showing which attachment matched the search result.

See: Lucene Full Text Search Indexing