photoanalysisd should not be running, while you are working with Photos. Are sou seeing it using CPU time, while you are browsing or editing photos?
The safest way to prevent photoanalysisd from running is using Photos - while you are browsing or editing Photos, the process should not be running. And if you are not using Photos unplug the drive with your Photos Library. The process cannot run, if there is no Photos Library on any mounted drive.
You can kill or stop a process from the Terminal using the command launchctl, but killing alone will not suffice, because Photos will just restart the process again. You would have to disable photoanalysisd from ever running again.
into a Terminal window to see the documentation for this command.
This command will disable photoanalysisd:
launchctl disable gui/$UID/com.apple.photoanalysisd
And this will kill the currently running process, after you disabled it.
launchctl kill -TERM gui/$UID/com.apple.photoanalysisd
To enable it again, use
launchctl enable gui/$UID/com.apple.photoanalysisd
But Photos 3.0 is not of much use, if you prevent it from collecting the categories, places, faces. I#d let the process run during the night, to get the task done.