Updated 2023-03-20: the “Recents” tab in Finder will also clear as a result of changing this.
Are you using the Spotlight or Recents feature on your Mac? If not, here’s a quick way to extend battery life and speed up your system.
Spotlight uses a background process called mdworker to index your disk.
Especially on older Macs, and especially after changing lots of files on your
disk, you may have been bitten by said process munching CPU one or the other
time.
There’s a command-line tool called mdutil that can be used (with sudo) to
manage the indexing process. You can view the indexing status of all your disks
using sudo mdutil -as (-a to apply the command to all stores on all volumes,
-s to display indexing status).
Finally, to switch it off on all volumes, run:
$ sudo mdutil -a -i off
You can verify using sudo mdutil -as again and enjoy a more quiet Mac
experience.