I took some time time today to evaluate and learn about FoundationDB. One immediate limitation I noticed was the inability for an individual key to store more than 100 kB.
Various pages of documentation that note this limitation all link to the following page RE writing a workaround, however this page seems to be incomplete: https://apple.github.io/foundationdb/largeval.html
That page promises to provide a “tutorial [that] illustrates techniques for storing and managing large values in FoundationDB” but trails off before doing so.
I recommend that this page be prominently marked as incomplete to reduce confusion or actually be completed.
By searching through the forums I was able to find a link to the following recipe for storing blobs in FoundationDB, which may be useful in completing that page: https://apple.github.io/foundationdb/blob.html
As a completely new user of FoundationDB I am not qualified to integrate that information myself.