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  • AvroSerDe

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Comment: add link to HIVE-7446 for adding columns in 0.14.0

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  • Infers the schema of the Hive table from the Avro schema. Starting in Hive 0.14, the Avro schema can be inferred from the Hive table schema.
  • Reads all Avro files within a table against a specified schema, taking advantage of Avro's backwards compatibility abilities
  • Supports arbitrarily nested schemas.
  • Translates all Avro data types into equivalent Hive types. Most types map exactly, but some Avro types don't exist in Hive and are automatically converted by the AvroSerde.
  • Understands compressed Avro files.
  • Transparently converts the Avro idiom of handling nullable types as Union[T, null] into just T and returns null when appropriate.
  • Writes any Hive table to Avro files.
  • Has worked reliably against our most convoluted Avro schemas in our ETL process.
  • Starting in Hive 0.14, columns can be added to an Avro backed Hive table using the Alter Table statement.

For general information about SerDes, see Hive SerDe in the Developer Guide. Also see SerDe for details about input and output processing.

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