adamreichold
commented
2 months ago redb is not an in-memory key-value store but a persistent database first. It only uses a built-in in-memory cache, c.f. set_cache_size, to avoid costly I/O to improve performance.
redb states itself an embedded kv stoe, but it still defines a file format and create a data file. I wonder if redb supports spilling data on disk if memory is exhausted.