Hacker News Reader

The last time I checked, MySQL still can’t do foreign keys with binary blobs. (I think it works with some very specific limitations but not enough to actually use in the real world.)

View on HN

I have the strong feeling I would never do this regardless of the DB engine for performance and storage reasons. I would try to hash the blob into a bigint and use that as the PK/FK.

Out of curiosity, is there a scenario you can share in which using a binary blob as a PK/FK would be the best solution?

I'm not talking huge blobs, just (fixed-size) 8- to 16-byte uuid-like fields. You can obviously marshal 8-byte fields to a bigint but you can't do that with 16-byte fields.

Reply on news.ycombinator.com