Hi,
Thanks for reaching out and trying CrateDB.
For information on using CrateDB with NiFi please take a look at Connecting to CrateDB from Apache NiFi - Tutorials - CrateDB Community
Regarding the storage of binary files in CrateDB, you would probably be looking at Exploring Blob storage in CrateDB - Tutorials - CrateDB Community
If the files are small, there is also the option of Base64 encoding them and then storing them in a TEXT INDEX OFF STORAGE WITH (columnstore = false) column.
I hope this helps, do not hesitate to reach out again if you have any further questions.