Minimal working example of storing numpy vectors in sqlite3 using Python:

    import sqlite3
    from scipy.spatial.distance import cdist
    import numpy as np

    class Vector:
        def __init__(self, arg):
            self.arg = arg

        def __str__(self):
            return 'Vector({!r})'.format(self.arg)


    def adapter_func(obj: np.ndarray):
        return obj.tobytes()

    def converter_func(data: bytes):
        return np.frombuffer(data)

    sqlite3.register_adapter(Vector, adapter_func)
    sqlite3.register_converter(f"{Vector.__name__}", converter_func)

    if __name__ == '__main__':
        with sqlite3.connect(":memory:", detect_types=sqlite3.PARSE_DECLTYPES) as con:
            cur = con.cursor()
            cur.execute("create table test(v vector)")
            cur.execute("insert into test(v) values (?)", (np.random.random(1280),))
            cur.execute("insert into test(v) values (?)", (np.random.random(1280),))

            cur.execute('select v from test')
            vectors = []
            for v, in cur.fetchall():
                print(v.shape, v)
                assert isinstance(v, np.ndarray)
                vectors.append(v)

            assert len(vectors) == 2
            print(cdist(vectors[:1], vectors[1:], metric='cosine')[0])

            cur.close()