long totalByteLength = columnChunkMetaData.getTotalUncompressedSize();
long start = columnChunkMetaData.getFirstDataPageOffset();
try {
FSDataInputStream f = fs.open(path);
this.dataReader = new ColumnDataReader(f, start, totalByteLength);
if (columnChunkMetaData.getDictionaryPageOffset() > 0) {
f.seek(columnChunkMetaData.getDictionaryPageOffset());
PageHeader pageHeader = Util.readPageHeader(f);
assert pageHeader.type == PageType.DICTIONARY_PAGE;
BytesInput bytesIn = parentColumnReader.parentReader.getCodecFactoryExposer()