parquet-hadoop/src/main/java/org/apache/parquet/hadoop/ParquetFileWriter.java
@Deprecated
  public static void writeMergedMetadataFile(List<Path> files, Path outputPath, Configuration conf) throws IOException {
    ParquetMetadata merged = mergeMetadataFiles(files, conf);
    writeMetadataFile(outputPath, merged, outputPath.getFileSystem(conf));
  }
@Deprecated
  public static void writeMergedMetadataFile(List<Path> files, Path outputPath, Configuration conf) throws IOException {
    ParquetMetadata merged = mergeMetadataFiles(files, conf);
    writeMetadataFile(outputPath, merged, outputPath.getFileSystem(conf));
  }
Given a list of metadata files, merge them into a single metadata file.
Requires that the schemas be compatible, and the extraMetaData be exactly equal.
This is useful when merging 2 directories of parquet files into a single directory, as long
as both directories were written with compatible schemas and equal extraMetaData.
@param files a list of files to merge metadata from
@param outputPath path to write merged metadata to
@param conf a configuration
@throws IOException if there is an error while reading or writing
@deprecated metadata files are not recommended and will be removed in 2.0.0