[geoduck14]

>I think the only thing that can tell us whether or not every database can be a vector database is time.

I can help you put right now. You don't even need a database to have a "vector database". FAISS is an in-memory "vector database" that runs on the data that you happen to have. So: if you data is stored in a .txt file, load it into memory, index it with FAISS... bam a vector database from a data file.

Can we take X arbitrary "real" database and implement KNN search on top of 1000 indexed columns, I'm sure it is possible - but I'm also pretty sure most databases will die under the pressure (source: I've asked some of my favorite DBAs if I could do this and they said "no")