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https://issues.apache.org/jira/browse/HIVE-10642?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14532945#comment-14532945
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Dong Chen commented on HIVE-10642:
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Thanks for your quick feedback, [~spena]! I will rename and make code clean
based on your comment tomorrow.
About the precise, yes, new timestamp data type is less precise. It is {{the
number of milliseconds from the Unix epoch, 00:00:00.000 on 1 January 1970,
UTC.}}. Original is nanoseconds.
I checked the test case {{parquet_external_time.q}}, using more precise
timestamp value, which is generated by old support. The selected value keeps
the precise. So I think this should be ok and backward compatible.
> Update Timestamp type mapping to Parquet
> -----------------------------------------
>
> Key: HIVE-10642
> URL: https://issues.apache.org/jira/browse/HIVE-10642
> Project: Hive
> Issue Type: Sub-task
> Reporter: Dong Chen
> Assignee: Dong Chen
> Attachments: HIVE-10642-parquet.patch
>
>
> Timestamp in Hive was originally mapped to INT_96 in Parquet before. And
> inside Parquet it use Binary to save values.
> When working on HIVE-10255, I found predicate with timestamp does not work,
> since comparing Binary representative of Timestamp value can not give correct
> relationship.
> Meanwhile, in latest version Parquet, the timestamp is mapped to INT_64.
> Refer to https://github.com/Parquet/parquet-format/blob/master/LogicalTypes.md
> Therefore, this Jira will update the mapping of Timestamp type in Hive, and
> keep it backward compatible.
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