Twproject indexes every text saved in its objects, like tasks, documents, attachments, issues, resources, comments and so on.
It uses the powerful search engine open source Lucene.
http://lucene.apache.org/java/docs/index.html
There are some parameters you can configure:
First of all the index files location, then the analyzer language. This analyzer is used to stem correctly your data. Stemming allows you to search “work” and find also “working”, of course it works correctly when the language you are writing data and the stemmer match.
In any case Twproject uses also exact matching in searches.
By following the “index management” link:
Here you can see the indexing machine status, stop the indexing job or force re-indexing.
Hits management page
Hits are used by Twproject to compute group rank. All “hit” data is de-normalized to maximize performance, so there is a scheduled action to “clean up” hits.
Hits are automatically cleaned and maintained, eventually you may use this page to “have a look” and eventually repair hits.