presto-hive/src/main/java/io/prestosql/plugin/hive/metastore/file/FileHiveMetastore.java/FileHiveMetastore/getPartitionStatistics
class FileHiveMetastore:    @Override
    public synchronized Map<String, PartitionStatistics> getPartitionStatistics(HiveIdentity identity, String databaseName, String tableName, Set<String> partitionNames)
    {
        Table table = getRequiredTable(databaseName, tableName);
        ImmutableMap.Builder<String, PartitionStatistics> statistics = ImmutableMap.builder();
        for (String partitionName : partitionNames) {
            List<String> partitionValues = extractPartitionValues(partitionName);
            Path partitionDirectory = getPartitionMetadataDirectory(table, ImmutableList.copyOf(partitionValues));
            PartitionMetadata partitionMetadata = readSchemaFile("partition", partitionDirectory, partitionCodec)
                    .orElseThrow(() -> new PartitionNotFoundException(new SchemaTableName(databaseName, tableName), partitionValues));
            HiveBasicStatistics basicStatistics = getHiveBasicStatistics(partitionMetadata.getParameters());
            statistics.put(partitionName, new PartitionStatistics(basicStatistics, partitionMetadata.getColumnStatistics()));
        }
        return statistics.build();
    }