/*
 *   .elementAnd("foo[]")
 *     .is("a", Op.LESS, 10)
 *     .is("b", Op.GREATER, 8)
 *     .close()
 */
select d, e from dfs.`%1$s` where _id in (
  select _id
    from (select _id, flatten(foo) as f1 from dfs.`%1$s`) as t1
    where t1.f1.a < 10 and t1.f1.b > 8
    )
