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https://issues.apache.org/jira/browse/HIVE-21290?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16798977#comment-16798977
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Hive QA commented on HIVE-21290:
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Here are the results of testing the latest attachment:
https://issues.apache.org/jira/secure/attachment/12963386/HIVE-21290.3.patch
{color:green}SUCCESS:{color} +1 due to 3 test(s) being added or modified.
{color:green}SUCCESS:{color} +1 due to 15837 tests passed
Test results:
https://builds.apache.org/job/PreCommit-HIVE-Build/16631/testReport
Console output: https://builds.apache.org/job/PreCommit-HIVE-Build/16631/console
Test logs: http://104.198.109.242/logs/PreCommit-HIVE-Build-16631/
Messages:
{noformat}
Executing org.apache.hive.ptest.execution.TestCheckPhase
Executing org.apache.hive.ptest.execution.PrepPhase
Executing org.apache.hive.ptest.execution.YetusPhase
Executing org.apache.hive.ptest.execution.ExecutionPhase
Executing org.apache.hive.ptest.execution.ReportingPhase
{noformat}
This message is automatically generated.
ATTACHMENT ID: 12963386 - PreCommit-HIVE-Build
> Restore historical way of handling timestamps in Parquet while keeping the
> new semantics at the same time
> ---------------------------------------------------------------------------------------------------------
>
> Key: HIVE-21290
> URL: https://issues.apache.org/jira/browse/HIVE-21290
> Project: Hive
> Issue Type: Sub-task
> Reporter: Zoltan Ivanfi
> Assignee: Karen Coppage
> Priority: Major
> Attachments: HIVE-21290.1.patch, HIVE-21290.2.patch,
> HIVE-21290.2.patch, HIVE-21290.3.patch
>
>
> This sub-task is for implementing the Parquet-specific parts of the following
> plan:
> h1. Problem
> Historically, the semantics of the TIMESTAMP type in Hive depended on the
> file format. Timestamps in Avro, Parquet and RCFiles with a binary SerDe had
> _Instant_ semantics, while timestamps in ORC, textfiles and RCFiles with a
> text SerDe had _LocalDateTime_ semantics.
> The Hive community wanted to get rid of this inconsistency and have
> _LocalDateTime_ semantics in Avro, Parquet and RCFiles with a binary SerDe as
> well. *Hive 3.1 turned off normalization to UTC* to achieve this. While this
> leads to the desired new semantics, it also leads to incorrect results when
> new Hive versions read timestamps written by old Hive versions or when old
> Hive versions or any other component not aware of this change (including
> legacy Impala and Spark versions) read timestamps written by new Hive
> versions.
> h1. Solution
> To work around this issue, Hive *should restore the practice of normalizing
> to UTC* when writing timestamps to Avro, Parquet and RCFiles with a binary
> SerDe. In itself, this would restore the historical _Instant_ semantics,
> which is undesirable. In order to achieve the desired _LocalDateTime_
> semantics in spite of normalizing to UTC, newer Hive versions should record
> the session-local local time zone in the file metadata fields serving
> arbitrary key-value storage purposes.
> When reading back files with this time zone metadata, newer Hive versions (or
> any other new component aware of this extra metadata) can achieve
> _LocalDateTime_ semantics by *converting from UTC to the saved time zone
> (instead of to the local time zone)*. Legacy components that are unaware of
> the new metadata can read the files without any problem and the timestamps
> will show the historical Instant behaviour to them.
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