Hello CCleaner team,
a while ago, after clearing my Windows Desktop Search index (which was about 8GB in size), I noticed that the free space in the index file (windows.eds) was not automatically reclaimed by WDS even after many reboots, so I suspect that the service will never clean up its database at all. I was quite surprised to be able to reclaim over 7 GB of space that way, and posted a note about this experience in one of Microsoft's community forums:
It occurred to me that this might be a useful feature to include in CCleaner as well, as many people might not even be aware of the index size that WDS is accumulating, and an easy tool to reclaim space and remove traces of long-deleted files would be quite helpful.
I have not got a lot of data about how much wasted space this will usually return, but at least in my case the impact was significant. I just tried this again, and the index shrunk once more from 272M to 12M.
ciao marcus