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https://issues.apache.org/jira/browse/HIVE-20346?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16593186#comment-16593186
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wuchang commented on HIVE-20346:
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[~sershe] Great thanks for your precious comment.
Yes, the operation based downgrade will cause many unexpected side effect AND
need many many test and verification.
My team has another solution to achieve a smooth rollback in
[HIVE-20398|https://issues.apache.org/jira/browse/HIVE-20398], the main idea is
to keep old version hive metastore db synchronized with the new version hive
metastore db with a remote call plugin.
What's your opinion?
> [Hive Upgrade] A rollback script is necessary when upgrade hive
> ---------------------------------------------------------------
>
> Key: HIVE-20346
> URL: https://issues.apache.org/jira/browse/HIVE-20346
> Project: Hive
> Issue Type: Task
> Reporter: wuchang
> Assignee: wuchang
> Priority: Major
>
> When we upgrade hive from a low version(1.1.0) to higher version(2.3.3), we
> will have to:
> # backup the old hive metastore database
> # Use schema tool to upgrade the hive metastore database schema.
> Then several days after the upgrading, new version hive have some critical
> problems and we want to revert to previous hive, what could we do? Since
> during these days the data in hive metastore has changed. So, if we directly
> switch to the old hive metastore, any metadata changes after the upgrading
> will lose.
> So , I think we need a rollback script, which is used to downgrade our high
> version metastore schema to low version schema.
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