I think persistence is another area that requires the use of text files. However, if you follow this you will only need to set persistence up once and they you can forget about it.
Persistence is one of those things that tend to be forgotten about when talking about these higher level topics. Its important though and shouldn’t be.
Since you are looking at persistence right now, I’ll go ahead and point you to the InfluxDB+Grafana Tutorial if you have any interest at all in generating charts in the future. There is charting built in to OH but it is very much what-you-see-is-what-you-get with no real ability to customize it. Grafana has full customization abilities.