
```
select *
from (
select 'table' as table, toInt64(10) as rows, toInt64(101) as elements
union all
select 'another table' as table, toInt64(0) as rows, toInt64(0) as elements
)
where rows - elements <> 0

DB::Exception: Block structure mismatch in Pipe::unitePipes stream: different number of columns:
table String String(size = 0), rows Int64 Int64(size = 0), elements Int64 Int64(size = 0)
table String String(size = 0), rows Int64 Int64(size = 0), elements Int64 Int64(size = 0), dummy UInt8 UInt8(size = 0) (version 21.5.3.1 (official build))
```
}
            }
        }
    }
    for (const auto * node : index)
        second_index.push_back(data[node].to_second);
    NodeRawConstPtrs second_inputs;
    NodeRawConstPtrs first_inputs;
    for (const auto * input : inputs)
    {
        const auto & cur = data[input];
        first_inputs.push_back(cur.to_first);
    }
    for (const auto * input : new_inputs)
    {
        const auto & cur = data[input];
        second_inputs.push_back(cur.to_second);
        first_index.push_back(cur.to_first);
    }
    auto first_actions = std::make_shared<ActionsDAG>();
    first_actions->nodes.swap(first_nodes);
    first_actions->index.swap(first_index);
    first_actions->inputs.swap(first_inputs);
    auto second_actions = std::make_shared<ActionsDAG>();
    second_actions->nodes.swap(second_nodes);
    second_actions->index.swap(second_index);
    second_actions->inputs.swap(second_inputs);
    return {std::move(first_actions), std::move(second_actions)};
}
ActionsDAG::SplitResult ActionsDAG::splitActionsBeforeArrayJoin(const NameSet & array_joined_columns) const