@Override
    public void write(Writable w) throws IOException {
      Text t = (Text)w;
      os.writeBytes(t.toString());
      os.writeBytes("\n");
    }
This is bogus especially with split update acid tables.  This causes compaction to create
delete_delta_x_y where none existed before.  Makes the data layout such as would never be
created by 'real' code path.
ql/src/test/org/apache/hadoop/hive/ql/txn/compactor/CompactorTest.java