Listing all parts in log have no sense. 
Should be either silenced, either combined into a single line.
MergeTreeData::DataPartsVector parts,
        const Names & column_names,
        const StorageMetadataPtr & metadata_snapshot,
        const SelectQueryInfo & query_info,
        const Context & context,
        UInt64 max_block_size,
        unsigned num_streams,
        const PartitionIdToMaxBlock * max_block_numbers_to_read = nullptr) const;
private:
    const MergeTreeData & data;
    Poco::Logger * log;
    QueryPlanPtr spreadMarkRangesAmongStreams(
        RangesInDataParts && parts,
        size_t num_streams,
        const Names & column_names,
        const StorageMetadataPtr & metadata_snapshot,
        UInt64 max_block_size,
        bool use_uncompressed_cache,
        const SelectQueryInfo & query_info,
        const Names & virt_columns,
        const Settings & settings,
        const MergeTreeReaderSettings & reader_settings,
        const String & query_id) const;
    
    QueryPlanPtr spreadMarkRangesAmongStreamsWithOrder(
        RangesInDataParts && parts,
        size_t num_streams,
        const Names & column_names,
        const StorageMetadataPtr & metadata_snapshot,
        UInt64 max_block_size,