21.7.3 throws an exception if `_sample_factor` is used in a query:
```
CREATE TABLE sessions
(
  `user_id` UInt64
)
ENGINE = MergeTree
ORDER BY user_id 
SAMPLE BY user_id;

insert into sessions values(1);

SELECT
    sum(user_id * _sample_factor) 
FROM sessions
SAMPLE 10000000

DB::Exception: Cannot find column `user_id` in source stream (version 21.8.1.7409 (official build))

SELECT
    sum(user_id) 
FROM sessions
SAMPLE 10000000

sum(user_id)
------------
           1
```
No exception on 21.6.5
{
    auto result = selectRangesToRead(prepared_parts);
    std::string prefix(format_settings.offset, format_settings.indent_char);
    format_settings.out << prefix << "ReadType: " << readTypeToString(result.read_type) << '\n';
    if (!result.index_stats.empty())
    {
        format_settings.out << prefix << "Parts: " << result.index_stats.back().num_parts_after << '\n';
        format_settings.out << prefix << "Granules: " << result.index_stats.back().num_granules_after << '\n';
    }
}
void ReadFromMergeTree::describeActions(JSONBuilder::JSONMap & map) const
{
    auto result = selectRangesToRead(prepared_parts);
    map.add("Read Type", readTypeToString(result.read_type));
    if (!result.index_stats.empty())
    {
        map.add("Parts", result.index_stats.back().num_parts_after);
        map.add("Granules", result.index_stats.back().num_granules_after);
    }
}
void ReadFromMergeTree::describeIndexes(FormatSettings & format_settings) const