Toke Eskildsen & Mikkel Kamstrup Erlandsen, State and University Library, Denmark
We wanted search result faceting at our library. Just the basics with tags for material type, author and such. We found a suitable hammer and now have distributed faceting for 100 million documents with 10 times that number of unique tags. All in sync with Lucene indexes. We had to cheat a bit, but you don't see that when we wave our hands. We'll talk about why brute force and cheating is fine.
Slides in PDF