@dispatch(Projection, sa.Column)
def compute_up(expr, data, **kwargs):
    selectables = [
        compute(
            expr._child[field],
            data,
            post_compute=False,
            return_type='native',
        )
        for field in expr.fields
    ]
    froms = set(concat(s.froms for s in selectables))
    assert 1 <= len(froms) <= 2
    result = unify_froms(sa.select(first(sel.inner_columns)
                                   for sel in selectables),
                         froms)
    return result.where(unify_wheres(selectables))
dataset/ETHPy150Open blaze/blaze/blaze/compute/sql.py/compute_up/original