Multiple files for a single SQLite database

I found out, that it is possible.

Use:

sqlite3.exe MainDB.db

ATTACH DATABASE 'SomeTableFile.db' AS stf;

Access the table from the other database file:

SELECT * FROM stf.SomeTable;

You can even join over several files:

SELECT *
FROM MainTable mt
JOIN stf.SomeTable st
ON (mt.id = st.mt_id);

https://www.sqlite.org/lang_attach.html

tameera said there is a limit of 62 attached databases but I never hit that limit so I can’t confirm that.

The big advantage besides some special cases is that you limit the fragmentation in the database files and you can use the VACUUM command separately on each table!