[[de:Benutzer:Joma]] has written a fast search engine for a Wikipedia mirror which can handle complex search queries. He emphasises that it's meant as a supplement to an existing SQL database, not a replacement. He is willing to put the code under GPL if we are interested.
I think this might be useful for us, could one of the German speaking developers please take a look at http://de.wikipedia.org/wiki/Wikipedia_Diskussion:Projekte%2C_die_Wikipedia_... and - if we want to give it a try - get in contact with Joma?
Kurt