It looks like what @nibbles said, you aren’t using the correct executable.
Since this looks to be in a docker image, be sure you are running this command from within that image. For example “docker exec -it ”
Then make sure you are running “sqlite3 com.plexapp.plugins.library.db” on the files you are trying to change this page file. Your command here looks like you are trying to also vacuum the DB and other SQL maintenance tasks. Plex’s version of SQLite is custom and it’s recommended you use their executable to make changes.
Lastly, this fix only helps if you are running the Plex DB from a HDD or slower SSD.
If you are running on anything recent or NVMe (or even a RAM drive) you won’t see much of a benefit, but I keep it since my server has lots of RAM that I don’t mind be being used for this purpose.
Follow the commands exactly, but from within the docker image and this should work just fine. A successful output is just a new line, then you Ctrl + D to exit SQLite
