presto-hive/src/main/java/io/prestosql/plugin/hive/statistics/MetastoreHiveStatisticsProvider.java/MetastoreHiveStatisticsProvider/createDataColumnStatistics
class MetastoreHiveStatisticsProvider:    @VisibleForTesting
    static ColumnStatistics createDataColumnStatistics(String column, Type type, double rowsCount, Collection<PartitionStatistics> partitionStatistics)
    {
        List<HiveColumnStatistics> columnStatistics = partitionStatistics.stream()
                .map(PartitionStatistics::getColumnStatistics)
                .map(statistics -> statistics.get(column))
                .filter(Objects::nonNull)
                .collect(toImmutableList());

        if (columnStatistics.isEmpty()) {
            return ColumnStatistics.empty();
        }

        return ColumnStatistics.builder()
                .setDistinctValuesCount(calculateDistinctValuesCount(columnStatistics))
                .setNullsFraction(calculateNullsFraction(column, partitionStatistics))
                .setDataSize(calculateDataSize(column, partitionStatistics, rowsCount))
                .setRange(calculateRange(type, columnStatistics))
                .build();
    }