private static boolean isS3(FileSystem fs) {
    try {
      return "s3a".equalsIgnoreCase(fs.getScheme());
    } catch (UnsupportedOperationException ex) {
      // Some FS-es do not implement getScheme, e.g. ProxyLocalFileSystem.
      return false;
    }
  }
Create row key and value object inspectors for reduce vectorization.
The row object inspector used by ReduceWork needs to be a **standard**
struct object inspector, not just any struct object inspector.
@param keyInspector
@param valueInspector
@return OI
@throws HiveException
ql/src/java/org/apache/hadoop/hive/ql/exec/Utilities.java