>2 things I haven't been able to establish:
>
>1) Where is data stored - single file or multiple files? and
Only from (very interested!) reading: it is a "pure" column DB, typically storing each column as a single file.
I think there were hints at two options: storing large parts of columns as streams in same file and defining tuples as stream content, if they are always accessed in that way (think variables of larger DS included in multiple correlation). Did not verify follow up.

One thing I am certain: it is NOT the "RAM-optimising-sparse" way of storing (RowID, ColID, Value) Oracle aims for which is gold for DB structures with 60-90 % of colums columns being null/empty/unknown, which does fit more data into RAM.
>
>2) None of the examples includes credentials. Does it have encryption/security?

Did not come across such a fact. Probably relying on OS security of directory of data files at first, and throwing encryption into RAM access is orthogonal to speed of access ;-))