I\'m building a Django site and I am looking for a search engine.
A few candidates:
Lucene/Lucene with Compass/Solr
Sphinx
I am surprised that there isn't more information posted about Solr. Solr is quite similar to Sphinx but has more advanced features (AFAIK as I haven't used Sphinx -- only read about it).
The answer at the link below details a few things about Sphinx which also applies to Solr. Comparison of full text search engine - Lucene, Sphinx, Postgresql, MySQL?
Solr also provides the following additional features:
BTW, there are tons more features; however, I've listed just the features that I have actually used in production. BTW, out of the box, MySQL supports #1, #3, and #11 (limited) on the list above. For the features you are looking for, a relational database isn't going to cut it. I'd eliminate those straight away.
Also, another benefit is that Solr (well, Lucene actually) is a document database (e.g. NoSQL) so many of the benefits of any other document database can be realized with Solr. In other words, you can use it for more than just search (i.e. Performance). Get creative with it :)