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https://issues.apache.org/jira/browse/HIVE-25104?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17542926#comment-17542926
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Stamatis Zampetakis commented on HIVE-25104:
--------------------------------------------
The changes in this ticket accidentally introduced some inconsistency between
vectorized and non-vectorized reader on the way they determine which conversion
to use to read the data. HIVE-26270 aims to re-align the behavior so this
ticket should always be backported together with HIVE-26270.
> Backward incompatible timestamp serialization in Parquet for certain timezones
> ------------------------------------------------------------------------------
>
> Key: HIVE-25104
> URL: https://issues.apache.org/jira/browse/HIVE-25104
> Project: Hive
> Issue Type: Bug
> Components: Serializers/Deserializers
> Affects Versions: 3.1.0
> Reporter: Stamatis Zampetakis
> Assignee: Stamatis Zampetakis
> Priority: Major
> Labels: compatibility, pull-request-available, timestamp
> Fix For: 4.0.0, 4.0.0-alpha-1
>
> Time Spent: 2h
> Remaining Estimate: 0h
>
> 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
> Parquet 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 37f13b02dff94e310d77febd60f93d5a205254d3
> {code:sql}
> CREATE EXTERNAL TABLE employee(eid INT,birth timestamp) STORED AS PARQUET
> 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;
> {code}
> |1|1880-01-01 00:00:00|
> |2|1884-01-01 00:00:00|
> |3|1990-01-01 00:00:00|
> At apache/branch-2.3 commit 324f9faf12d4b91a9359391810cb3312c004d356
> {code:sql}
> CREATE EXTERNAL TABLE employee(eid INT,birth timestamp) STORED AS PARQUET
> LOCATION '/tmp/hiveexttbl/employee';
> SELECT * FROM employee;
> {code}
> |1|1879-12-31 23:52:58|
> |2|1884-01-01 00:00:00|
> |3|1990-01-01 00:00:00|
> The timestamp for {{eid=1}} in branch-2.3 is different from the one in master.
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