Thanks for the insight, Kevin, but I prefer to quit Safari periodically, because quitting clears the tracking cookies & caches (that Safari "stores" in RAM) that can't be cleared by any other means of which I'm aware.
Have you ever cleared (or seen) this one?
ls -lhn ~/Library/Caches/Metadata/Safari/History/.tracked\ filenames.plist
defaults read ~/Library/Caches/Metadata/Safari/History/.tracked\ filenames
/edit: Figured i should probably mention that those two orange lines are actually terminal commands. Running the first one (e.g., via copy/paste) will list a hidden file... if it exists. Doing that much will show us its size (among other things). Running the second command will display its content. Observe that, not only is the file hidden in Finder (via the leading dot in its name), but —for something sitting in a folder named "History" —it typically isn't affected when we clear Safari's history. In fact, i've been told that it even survives a 'Reset Safari...' menu operation. (idunno)
So far (despite posting about it far and wide), i have not learned this file's actual purpose (e.g., does it truly benefit the user?), nor which entity is "in charge" of it. [Apple?, Google? who?]
