presto-hive/src/main/java/io/prestosql/plugin/hive/SyncPartitionMetadataProcedure.java/SyncPartitionMetadataProcedure/isValidPartitionPath
class SyncPartitionMetadataProcedure:    private static boolean isValidPartitionPath(FileStatus file, Column column)
    {
        Path path = file.getPath();
        String prefix = column.getName() + '=';
        return file.isDirectory() && path.getName().startsWith(prefix);
    }