cold1 4.9 3.6
hot1 2.0 1.0
cold2 2.6 1.9
hot2 1.7 1.0
As can be seen, the optimization effects both hot and cold cache times which is quite handy as there are many times I use both, starting with a "-Z" evalutation to see how many matches there are and specializing or generalizing the query from there.
While the numbers may seem large, keep in mind that this is a slow arm running from an IO interface that needs some TLC. Using this indexing on an N9 or desktop machine will be much quicker even if there are 10 times the number of files indexed.
These arm deb builds will be up on fuuko.libferris.com sometime soon. I have to do a release of libferris with this optimization and the funky new JSON/REST support too.