BeFS extended file attributes are a good example to point out. I watched this excellent talk which shows the power of live queries: https://systemswe.love/archi

BeFS extended file attributes are a good example to point out. I watched this excellent talk which shows the power of live queries: https://systemswe.love/archive/minneapolis-2017/ivan-richwalski https://systemswe.love/archive/minneapolis-2017/ivan-richwal... Unfortunately, file attributes is not a feature I want to see. They don't solve the problems with naming files or deduplicating files. Metadata is attached to a file, so when the file is gone the metadata is gone. I instead proposed that metadata can be freestanding, and can exist even if the main file is missing. Relevant section to read: https://www.nayuki.io/page/designing-better-file-organization-around-tags-not-hierarchies#internal-vs-external-metadata https://www.nayuki.io/page/designing-better-file-organizatio... I did read the entire book "Practical File System Design with the Be File System", but didn't find it helpful for what I was working on. I can skip the low-level bits because I'll probably build on top of a NoSQL database or something.