I like. Word splitting is very interesting. Today, 2012, I would be hard pressed to provide a reason to use this technique. Splitting an index is a classic complexity/resource trade off (your index has a very predictable compact footprint). Again, today, memory is cheap, wide, uniform, and predictable. Indexes are now cheap and highly specialized. Complexity can be reduced for simplicity. Index specialization now becomes natural. My point here is that this solves a class of very expensive searches with ease, leading wildcard searches et al. Also, couldnt really tell from your code (you may be doing this), but reverse your trigrams in your generated query. If ordered properly, your search will be a lot more efficient.