That's not likely to happen. Nor will anyone else from any other company volunteer to walk you through their policies and infrastructure.
If a "history" isn't associated with a user then there is no issue there, on the other hand they can still run a mapreduce job on it and extrapolate spelling corrections for example.
You ought to at least include Google's blog post for the sake of completeness.
Of course they mine those longs, there is a lot of knowledge to be gleaned from them, mostly to improve their product. Also some places mandate some kind of data retention.
Deriving "history" from those logs doesn't matter much as long as they eventually get anonymized.
You should update your post to reflect the 9 month distinctions between search history and server logs.
Active web history on the other hand will still be associated with an account for as long as it's active (not solely to Google's benefit by the way).
I thought this stuff was already sorted years ago and is now common knowledge, it's like those people only now realizing that Gmail does contextual ad targeting, it's somehow disingenuous.
If a "history" isn't associated with a user then there is no issue there, on the other hand they can still run a mapreduce job on it and extrapolate spelling corrections for example.
You ought to at least include Google's blog post for the sake of completeness.