[jira] [Created] (SPARK-17114) Adding a 'GROUP BY 1' where first column is literal results in wrong answer

["Josh Rosen (JIRA)" <ji...@apache.org>]

Josh Rosen created SPARK-17114:
----------------------------------

             Summary: Adding a 'GROUP BY 1' where first column is literal results in wrong answer
                 Key: SPARK-17114
                 URL: https://issues.apache.org/jira/browse/SPARK-17114
             Project: Spark
          Issue Type: Bug
    Affects Versions: 2.0.0, 1.6.2
            Reporter: Josh Rosen


Consider the following example:

{code}
sc.parallelize(Seq(128, 256)).toDF("int_col").registerTempTable("mytable")

// The following query should return an empty result set because the `IN` filter condition is always false for this single-row table.
val withoutGroupBy = sqlContext.sql("""
  SELECT 'foo'
  FROM mytable
  WHERE int_col == 0
""")
assert(withoutGroupBy.collect().isEmpty, "original query returned wrong answer")

// After adding a 'GROUP BY 1' the query result should still be empty because we'd be grouping an empty table:
val withGroupBy = sqlContext.sql("""
  SELECT 'foo'
  FROM mytable
  WHERE int_col == 0
  GROUP BY 1
""")
assert(withGroupBy.collect().isEmpty, "adding GROUP BY resulted in wrong answer")
{code}

Here, this fails the second assertion by returning a single row. It appears that running {{group by 1}} where column 1 is a constant causes filter conditions to be ignored.

Both PostgreSQL and SQLite return empty result sets for the query containing the {{GROUP BY}}. 



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

---------------------------------------------------------------------
To unsubscribe, e-mail: issues-unsubscribe@spark.apache.org
For additional commands, e-mail: issues-help@spark.apache.org