License 2nd computer one license

What I’m trying to do here is to have a windows tablet as a backup to the main pos, just in case the main pos fails, crashes or have any technical problems so the sales won’t stop and we will have a windows tablet as a backup until we fix any problems with the main pos.
I understand that the second terminal has to have the db from the main computer or from a server, but is there any way to have this second computer independent from others? Has it’s own database?
So any problem happens, we will have a quick replacement until main problem is fixed

If it needs to be indipendent it will want it’s own dB.
Doing that though will mean it will not just carry on from where the other one left of.
Ie is you have open tickets they will not be on the second system.
Also you will need a second licence as licences are per DB