private void ensureCorrectSchemaEvolutionConfigs(JobConf conf) {
    boolean isSchemaEvolution = HiveConf.getBoolVar(conf, HiveConf.ConfVars.HIVE_SCHEMA_EVOLUTION);
    boolean isForcePositionalEvolution =
        HiveConf.getBoolVar(conf, HiveConf.ConfVars.HIVE_ORC_FORCE_POSITIONAL_SCHEMA_EVOLUTION);

    if (!isSchemaEvolution && isForcePositionalEvolution) {
      LOG.warn(
          "invalid schema evolution ({}) and force positional evolution ({}) pair, falling back to disabling both",
          isSchemaEvolution, isForcePositionalEvolution);
      HiveConf.setBoolVar(conf, HiveConf.ConfVars.HIVE_ORC_FORCE_POSITIONAL_SCHEMA_EVOLUTION, false);
    }
  }
Set context for this fetch operator in to the jobconf.
This helps InputFormats make decisions based on the scope of the complete
operation.
@param conf the configuration to modify
@param paths the list of input directories
ql/src/java/org/apache/hadoop/hive/ql/exec/FetchOperator.java