[IMPALA-2092] Query generator creates non-deterministic analytic queries

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Cannot Reproduce
• Affects Version/s: Impala 2.3.0
• Component/s: Infrastructure
• Labels: query_generator_development
• Target Version: Product Backlog
• Assignee: Unassigned
• Reporter: Taras Bobrovytsky
• Created: 22/Jun/15 21:26
• Updated: 28/Dec/20 06:53
• Resolved: 28/Dec/20 06:53

Description

Impala Query:

SELECT
LAG('644', 66) OVER (ORDER BY string_col ASC, tinyint_col) AS char_col,
LAG(COALESCE(306, -86, -391), 77) OVER (ORDER BY month ASC, smallint_col DESC) AS int_col
FROM alltypesagg
order by char_col desc, int_col desc
limit 15;

Equivalent Postgres Query:

SELECT
LAG('644' || '', 66) OVER (ORDER BY CAST(string_col AS BYTEA) ASC, tinyint_col) AS char_col,
LAG(COALESCE(306, -86, -391), 77) OVER (ORDER BY month ASC, smallint_col DESC) AS int_col
FROM alltypesagg
order by char_col desc, int_col desc
limit 15;

Impala Result:

+----------+---------+
| char_col | int_col |
+----------+---------+
| NULL     | NULL    |
| NULL     | NULL    |
| NULL     | NULL    |
| NULL     | NULL    |
| NULL     | NULL    |
| NULL     | NULL    |
| NULL     | NULL    |
| NULL     | NULL    |
| NULL     | NULL    |
| NULL     | NULL    |
| NULL     | NULL    |
| NULL     | NULL    |
| NULL     | NULL    |
| NULL     | 306     |
| NULL     | 306     |
+----------+---------+
Fetched 15 row(s) in 0.84s

Postgres Result:

 char_col | int_col 
----------+---------
          |        
          |        
          |        
          |        
          |        
          |        
          |        
          |        
          |        
          |        
          |        
          |        
          |     306
          |     306
          |     306
(15 rows)