For text-searching in Mongo, there are two options:
$regex
operator - however unless you have a simple prefix regexp, queries won't use an index, and will result in a full scan, which usually is slow- In Mongo 2.4, a new text index has been introduced. A
text
query will split your query into words, and do an or-search for documents including any of the words. Text indexes also eliminate some stop-words and have simple stemming for some languages (see the docs).
If you are looking for a more advanced full-text search engine, with more powerful tokenising, stemming, autocomplete etc., maybe a better fit would be e.g. ElasticSearch.