[ARROW-11323] [Rust][DataFusion] ComputeError("concat requires input of at least one array")) with queries with ORDER BY or GROUP BY that return no

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 3.0.1, 4.0.0
• Component/s: Rust - DataFusion
• Labels: pull-request-available
• External issue URL: https://github.com/apache/arrow/issues/27221
• Assignee: Andrew Lamb
• Reporter: Andrew Lamb
• Created: 19/Jan/21 21:52
• Updated: 11/Jan/23 08:18
• Resolved: 21/Jan/21 12:43

Description

If you run a SQL query in datafusion which has predicates that produces no rows that also includes a GROUP BY or ORDER BY clause, you get the following error:

Error of "ArrowError(ComputeError("concat requires input of at least one array"))"

Here are two test cases that show the problem: https://github.com/apache/arrow/blob/master/rust/datafusion/src/execution/context.rs#L889

    #[tokio::test]
    async fn sort_empty() -> Result<()> {
        // The predicate on this query purposely generates no results
        let results =
            execute("SELECT c1, c2 FROM test WHERE c1 > 100000 ORDER BY c1 DESC, c2 ASC", 4).await?;
        assert_eq!(results.len(), 0);
        Ok(())
    }


    #[tokio::test]
    async fn aggregate_empty() -> Result<()> {
        // The predicate on this query purposely generates no results
        let results = execute("SELECT SUM(c1), SUM(c2) FROM test where c1 > 100000", 4).await?;
        assert_eq!(results.len(), 0);
        Ok(())
    }

Issue Links

• links to: GitHub Pull Request #9275