is this true?

Please refer to the User Guide - Data Security - Data Availability Guarantee chapter.

I think it's unlikely, essentially both .json and .md are text files, so technically there's not much difference between them.

The biggest difference between .json and .md is human readability. Standard .md can be directly modified manually, but manually modifying .json is much more difficult. If you are not careful, it is easy to cause syntax errors and data exceptions, so we do not recommend modifying the .json directly, thank you.

Certainly, I will check this out. Thanks!

Thank you for your response.

I have a habit of collecting a large amount of data, and I prefer using SiYuan for my database needs. Unlike many who favor the .md format and use Obsidian, SiYuan suits me better. However, my concern lies in the long-term management and safety of my data, especially since I do not manually interact with JSON and all my actions are within SiYuan. I could soon have a large database over time. I'm seeking advice on precautions and considerations for storing a significant number of databases in SiYuan to avoid any data loss in the future. Any guidance on this matter would be greatly appreciated.