Seems like one of those "dump the folder" situations:

Code:
set theFolder to ((path to library folder from user domain) as Unicode text) & "Caches:Metadata:Safari:History"
tell application "Finder"
	if (exists folder theFolder) then
		display dialog "Are you sure you want to delete the folder 
 \"~/Library/Caches/Metadata/Safari/History\"?
Clicking OK will empty the Trash."
		delete folder theFolder
		empty
	else
		display dialog "Folder doesn't exist."
	end if
end tell

(Note that the above script assumes you're not someone who uses the Trash to store things you're not ready to delete yet!)

It appears that the contents of that folder are written to RAM when Safari is launched, so you need to quit Safari before trashing them or they'll be regenerated along with the folder whenever Safari next wants to write to it.

FWIW, .tracked filenames.plist, as mentioned elsewhere, seems to consist of the URLs of sites which came up as Google search results and were actually visited.

Last edited by alternaut; 03/08/12 03:00 PM. Reason: changed title

dkmarsh—member, FineTunedMac Co-op Board of Directors