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https://issues.apache.org/jira/browse/HIVE-16171?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15966335#comment-15966335
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Sankar Hariappan commented on HIVE-16171:
-----------------------------------------

Hi [~ekoifman], 
For this truncate table support with change management, there are few changes 
done to update the table stats.
Could you please have a look at it? 
I shall see couple of test failures due to this change where the result-logs 
have differences. But, I believe, the new code is fine and the result file 
should be updated for these 2 failed tests. Please give your opinion if I'm 
wrong.

Brief description of my change:
Base:
1. Update Stats (RowNum=0, NumOfFiles=0 etc).
2. AlterTable with new Stats. -- This effectively regenerate the stats from the 
table again and hence set to older values.
3. TruncateTable (Trash data files)
New Code:
1. TruncateTable (Trash data files)
2. Update Stats (RowNum=0, NumOfFiles=0 etc).
3. AlterTable with new Stats. This was tested and is working fine.

cc: [~thejas], [~sushanth]

> Support replication of truncate table
> -------------------------------------
>
>                 Key: HIVE-16171
>                 URL: https://issues.apache.org/jira/browse/HIVE-16171
>             Project: Hive
>          Issue Type: Sub-task
>          Components: repl
>    Affects Versions: 2.1.0
>            Reporter: Sankar Hariappan
>            Assignee: Sankar Hariappan
>              Labels: DR
>         Attachments: HIVE-16171.01.patch, HIVE-16171.02.patch, 
> HIVE-16171.03.patch, HIVE-16171.04.patch, HIVE-16171.05.patch
>
>
> Need to support truncate table for replication. Key points to note.
> 1. For non-partitioned table, truncate table will remove all the rows from 
> the table.
> 2. For partitioned tables, need to consider how truncate behaves if truncate 
> a partition or the whole table.
> 3. Bootstrap load with truncate table must work as it is just 
> loadTable/loadPartition with empty dataset.
> 4. It is suggested to re-use the alter table/alter partition events to handle 
> truncate.
> 5. Need to consider the case where insert event happens before truncate table 
> which needs to see their data files through change management. The data files 
> should be recycled to the cmroot path before trashing it.



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