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https://issues.apache.org/jira/browse/IMPALA-8265?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16785841#comment-16785841
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Andy Stadtler commented on IMPALA-8265:
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Yea I'd agree with your assessment that option 3.1 seems like the best option
and least impactful to existing queries but also the most work. I don't know
how much value adding the flag in option 1 really adds, probably end up just
confusing more people.
> Reject INSERT/UPSERT queries with ORDER BY and no OFFSET/LIMIT
> ---------------------------------------------------------------
>
> Key: IMPALA-8265
> URL: https://issues.apache.org/jira/browse/IMPALA-8265
> Project: IMPALA
> Issue Type: Improvement
> Reporter: Andy Stadtler
> Priority: Critical
>
> Currently Impala doesn't honor a order by without a limit or offset in a
> insert ... select operation. While Impala currently throws a warning it seems
> like this query should be rejected with the same message. Especially now with
> the UPSERT ability and Kudu its obvious logic to take a table of duplicate
> rows and use the following query.
> {code:java}
> UPSERT INTO kudu_table SELECT col1, col2, col3 FROM duplicate_row_table ORDER
> BY timestamp_column ASC;{code}
> Impala will happily take this query and write incorrect data. The same query
> works fine as a SELECT only query and it's easy to see where users would make
> the mistake of reusing it in an INSERT/UPSERT.
>
> Rejecting the query with the warning message would make sure the user knew
> the ORDER BY would not be honored and make sure they added a limit, changed
> their query logic or removed the order by.
>
> {quote}*Sorting considerations:* Although you can specify an {{ORDER BY}}
> clause in an {{INSERT ... SELECT}} statement, any {{ORDER BY}} clause is
> ignored and the results are not necessarily sorted. An {{INSERT ... SELECT}}
> operation potentially creates many different data files, prepared on
> different data nodes, and therefore the notion of the data being stored in
> sorted order is impractical.
> {quote}
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