So that was a decent rant, but what it didn’t include was the actual information required to reproduce this.

I tried this quickly:

    create table p (
        id number(19,0) not null,
        email varchar2(255 char) not null,
        thenumber number(38,0),
        primary key (id)
    )

s.createNativeQuery("select id, thenumber from p").getSingleResult()

And I got back a BigDecimal. Same thing with number(38,5). Same thing with number(19,5). Same for number(10,5). With number(19) I get a Long.

So this bug does not appear to affect my version of Oracle and its JDBC driver.

But then, I don’t actually know what you did.