Tracker. *ugh* don’t even get me started on a rant about Tracker… The GNome team forgot all about Linux philosophies somewhere along the way.
So how to completely disable Tracker, so it no longer indexes any files, and stop having any Tracker process running in the background? You can mask the Tracker systemd services to completely disable it
Source: How To Completely Disable Tracker, GNOME’s File Indexing And Search Tool – Linux Uprising Blog