SQLite Forum

Table and index in separate files
Well no.  The index b-tree has a different root page than the table b-tree.  They are not intermixed.  A page is EITHER an index page OR a table page.  Not a mishmash of both.

Also, in a relational database the pointers from one "thingimy" to another "thingimy" (whether that thingimy is a table or an index) is based on duplication of data, only the duplication of data, and nothing but the duplication of the data.  

Only more efficient CODASYL style databases store "pointers" between BDAM records.

While CODASYL style storage of record pointers is far more efficient and far more useful (and performant) than storing duplicated data, CODASYL style databases are pretty much unrecoverable if corrupted.

Data duplication defining relationships (rather than pointers) is the whole point of a relational database and the reason that it was invented.

You can emulate each format in the other.