Comment by wolfgang42

CDB is an interesting format, optimized for read-heavy write-rarely[1] random lookups on slow media. This isn’t a very common requirement these days, but it’s convenient for very specific use cases.

[1] You “update” by overwriting the entire file. This is remarkably fast and means that there’s no overhead/tracking for empty space, but it does mean you probably want this to be a fairly rare operation.

I rolled my own cdb reader library for a project a few years ago, and wrote up my notes on the format and its internals here: https://search.feep.dev/blog/post/2022-12-03-cdb-file-format