public void setSchemaEvolution(SchemaEvolution evolution) {
    this.evolution = evolution;
  }
Position provider used in absence of indexes, e.g. for serde-based reader, where each stream
is in its own physical 'container', always starting at 0, and there are no RGs.
llap-server/src/java/org/apache/hadoop/hive/llap/io/decode/OrcEncodedDataConsumer.java