I found part 1 of this series a DZone but there was no reference to part 2. I found part 2 by tracing the article back to its original blog post and seeing it was followed by part 2.
Using Finite State Transducers in Lucene
Finite State Transducers, Part 2
I won’t try to summarize the posts, they are short and heavy on links to more material but would quote this comment from the second article:
To test this, I indexed the first 10 million 1KB documents derived from Wikipedia’s English database download. The resulting RAM required for the FST was ~38% – 52% smaller (larger segments see more gains, as the FST “scales up” well). Not only is the RAM required much lower, but term lookups are also faster: the FuzzyQuery united~2 was ~22% faster.
If using less RAM and faster lookups are of interest to you, these posts should be on your reading list.