Method is_streamable

src/expr/src/relation.rs:3569–3571

True if the finishing does not require an ORDER BY. LIMIT and OFFSET without an ORDER BY _are_ streamable: without an explicit ordering we will skip an arbitrary bag of elements and return the first arbitrary elements in the remaining bag. The result semantics are still correct but maybe surprising for some users.

(&self, arity: usize)

    /// the first arbitrary elements in the remaining bag. The result semantics
    /// are still correct but maybe surprising for some users.
    pub fn is_streamable(&self, arity: usize) -> bool {
        self.order_by.is_empty() && self.project.iter().copied().eq(0..arity)
    }
}

impl RowSetFinishing<NonNeg<i64>, usize> {