And waits for them. That's pointless.
{
            TTLRecompressMergeSelector recompress_ttl_selector(
                    next_recompress_ttl_merge_times_by_partition,
                    current_time,
                    data_settings->merge_with_recompression_ttl_timeout,
                    metadata_snapshot->getRecompressionTTLs());
            parts_to_merge = recompress_ttl_selector.select(parts_ranges, max_total_size_to_merge);
            if (!parts_to_merge.empty())
                future_part.merge_type = MergeType::TTL_RECOMPRESS;
        }
    }
    if (parts_to_merge.empty())
    {
        SimpleMergeSelector::Settings merge_settings;
        
        merge_settings.max_parts_to_merge_at_once = data_settings->max_parts_to_merge_at_once;
        if (aggressive)
            merge_settings.base = 1;
        parts_to_merge = SimpleMergeSelector(merge_settings)
                            .select(parts_ranges, max_total_size_to_merge);
        
        if (parts_to_merge.size() == 1)
            throw Exception("Logical error: merge selector returned only one part to merge", ErrorCodes::LOGICAL_ERROR);
        if (parts_to_merge.empty())
        {
            if (out_disable_reason)
                *out_disable_reason = "There is no need to merge parts according to merge selector algorithm";
            return SelectPartsDecision::CANNOT_SELECT;
        }
    }