Searching for similar like acts_as_ferret with more_like_this does with other search engines

I've took a look at fulltext search engines for rails applications (acts_as_ferret, Solr, Thinking Sphinx etc.), especially their pros & cons. I found a very 开发者_运维知识库useful feature called more_like_this in acts_as_ferret, which finds similar records in database (great for similar products in eshops etc.). But I haven't seen anything like this by those others, does any of them have a similar easy-to-use feature like more_like_this in acts_as_ferret which offers the same functionality?

Solr has a similar feature. See http://wiki.apache.org/solr/MoreLikeThis and http://wiki.apache.org/solr/MoreLikeThisHandler.