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https://issues.apache.org/jira/browse/SQOOP-3288?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16371491#comment-16371491
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Attila Szabo commented on SQOOP-3288:
-------------------------------------
Hey [~dvoros],
The reason why I'm a bit concerned:
I've faced already clusters where a specific node was in a very different
timezone, than the rest of the cluster.
Executing job from that node would end up in different result, than from the
others.
Do we expect this behaviour? Do we really want to depend on the OS time?
Thanks,
Attila
> Incremental import's upper bound ignores session time zone in Oracle
> --------------------------------------------------------------------
>
> Key: SQOOP-3288
> URL: https://issues.apache.org/jira/browse/SQOOP-3288
> Project: Sqoop
> Issue Type: Bug
> Components: connectors/oracle
> Affects Versions: 1.4.7
> Reporter: Daniel Voros
> Assignee: Daniel Voros
> Priority: Major
> Fix For: 1.5.0
>
> Attachments: SQOOP-3288.1.patch
>
>
> At the moment we're using [{{SELECT SYSDATE FROM
> dual}}|https://github.com/apache/sqoop/blob/3153c3610da7e5db388bfb14f3681d308e9e89c6/src/java/org/apache/sqoop/manager/OracleManager.java#L652]
> when getting current time from Oracle.
> SYSDATE returns the underlying operating system's current time, while
> CURRENT_TIMESTAMP uses the session time zone. This could lead to problems
> during incremental imports *when Oracle's time zone is different from the OS*.
> Consider the following scenario when Oracle is configured to {{+0:00}}, while
> the OS is {{+5:00}}:
> ||Oracle time||OS time||Event||
> |2:00|7:00|{{sqoop import --last-value 1:00 ...}} => imports {{[1:00, 7:00)}}|
> |2:30|7:30|{{update ... set last_updated = current_timestamp ...}} => set to
> {{2:30}} *Won't be imported!*|
> |3:00|8:00|{{sqoop import --last-value 7:00 ...}} => imports {{[7:00, 8:00)}}|
> This way records updated within 5 hours after the last sqoop import won't get
> imported.
> Please note, that the example above assumes, that the user/administrator
> who's updating the Oracle table will use the current session time of Oracle
> when setting the "last updated" column of the table.
> I think the solution is to use CURRENT_TIMESTAMP instead of SYSDATE. Other
> connection managers, like MySQL or PostgreSQL are using that as well.
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