RDBMS shine on getbyId queries. Queries where the value starts with should also work well. But queries where the word is in the middle of the value or column generally don’t perform well. Since it’s just for personal use that might not matter too much. If you’re querying on exact values it’ll go pretty smooth. If you’re querying on ‘deniro’ while the value contains ‘bob deniro’ and others it’ll be less performant. But it’s possible it works well enough for your case.
Elasticsearch is well known for text searches and being incredibly flexible with queries and filtering. https://www.elastic.co/
Manticore is one that’s been on my check-it-out for I don’t know how long. It looks great imo: https://manticoresearch.com/
Open search: https://opensearch.org/
Disclaimer: I haven’t really used any RDBMS systems extensively for years so it’s possible there are some that added support for full text searches being more performant.
Aleph also seems to be able to cross reference data between documents. I don’t think any of the ones listed above do this. But I also don’t know if this is part of your requirements.
Protonvpn has a Killswitch: https://protonvpn.com/support/what-is-kill-switch
or are you in a different scenario where that doesn’t work?
I’ve configured my router to set up a VPN connection to proton ( wireguard config ). I then decide which devices gonout without vpn and which with VPN. ( Default being with VPN ). If the wireguard tunnel happens to go down, the devices can’t surf the web.