kind of a bag of attributes in a DB . . .

Say, you get lots of data and their corresponding metadata, which in
some cases may be undefined or undeclared (left as an empty string).
Think of youtube json files or the result of the "file" command.

I need to be able to "instantly" search that metadata and I think DBs
are best for such jobs and get some metrics out of it.

I know this is not exactly a kosher way to deal with data which can't
be represented in a nice tabular form, but I don't find the idea that
half way off either.

What is the pattern, anti-pattern or whatever relating to such design?

Do you know of such implementations with such data?

lbrtchx