1. Distributed filesystems do often use databases for metadata (FoundationDB for 3FS being a recent example)
2. Using a B+ tree for metadata is not much different from having a sorted index
3. Filesystems are a common enough usecase that skipping the abstraction complexity to co-optimize the stack is warranted
1. Distributed filesystems do often use databases for metadata (FoundationDB for 3FS being a recent example)
2. Using a B+ tree for metadata is not much different from having a sorted index
3. Filesystems are a common enough usecase that skipping the abstraction complexity to co-optimize the stack is warranted