[jira] [Created] (IMPALA-8265) Reject INSERT/UPSERT queries with ORDER BY and no OFFSET/LIMIT

["Andy Stadtler (JIRA)" <ji...@apache.org>]

Andy Stadtler created IMPALA-8265:
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             Summary: 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


Currently Impala doesn't honor a sort by without a limit or offset in a insert ... select operation. While we currently throw 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 UPSERT INTO kudu.table SELECT col1, col2, col3 FROM duplicate_row_table SORT BY timestamp_column ASC. 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 sort by would not be honored and make sure they added a limit or changed their query logic.

 

*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.



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