Backward incompatible timestamp serialization in Avro for certain timezones

HIVE-12192, HIVE-20007 changed the way that timestamp computations are performed and to some extend how timestamps are serialized and deserialized in files (Parquet, Avro).

In versions that include HIVE-12192 or HIVE-20007 the serialization in Avro files is not backwards compatible. In other words writing timestamps with a version of Hive that includes HIVE-12192/HIVE-20007 and reading them with another (not including the previous issues) may lead to different results depending on the default timezone of the system.

Consider the following scenario where the default system timezone is set to US/Pacific.

At apache/master commit eedcd82bc2d61861a27205f925ba0ffab9b6bca8

CREATE EXTERNAL TABLE employee(eid INT,birth timestamp) STORED AS AVRO
 LOCATION '/tmp/hiveexttbl/employee';
INSERT INTO employee VALUES (1, '1880-01-01 00:00:00');
INSERT INTO employee VALUES (2, '1884-01-01 00:00:00');
INSERT INTO employee VALUES (3, '1990-01-01 00:00:00');
SELECT * FROM employee;

At apache/branch-2.3 commit 324f9faf12d4b91a9359391810cb3312c004d356

CREATE EXTERNAL TABLE employee(eid INT,birth timestamp) STORED AS AVRO
 LOCATION '/tmp/hiveexttbl/employee';
SELECT * FROM employee;

The timestamp for eid=1 in branch-2.3 is different from the one in master.