[IMPALA-2383] Incorrect results due to incorrect plan (Nested Types)

• Type: Bug
• Status: Resolved
• Priority: Blocker
• Resolution: Fixed
• Affects Version/s: Impala 2.3.0
• Fix Version/s: Impala 2.3.0
• Labels: correctness nested_types query_generator
• Target Version: Impala 2.3.0
• Assignee: Alexander Behm
• Reporter: Taras Bobrovytsky
• Created: 22/Sep/15 20:24
• Updated: 24/Sep/15 04:41
• Resolved: 24/Sep/15 04:41

Description

The query should return 0 rows, but this is not the case.

Query:

SELECT 1
FROM table_1 t1
LEFT JOIN table_2 t2 ON (t2.field_34.field_40) = (t1.field_17)
INNER JOIN t2.field_32 t3

Plan:

+------------------------------------------------------------------------------------+
| Explain String                                                                     |
+------------------------------------------------------------------------------------+
| Estimated Per-Host Requirements: Memory=2.06GB VCores=2                            |
| WARNING: The following tables are missing relevant table and/or column statistics. |
| random_nested_db_0.table_1, random_nested_db_0.table_2                             |
|                                                                                    |
| 08:EXCHANGE [UNPARTITIONED]                                                        |
| |                                                                                  |
| 06:HASH JOIN [LEFT OUTER JOIN, BROADCAST]                                          |
| |  hash predicates: (t1.field_17) = (t2.field_34.field_40)                         |
| |                                                                                  |
| |--07:EXCHANGE [BROADCAST]                                                         |
| |  |                                                                               |
| |  02:SUBPLAN                                                                      |
| |  |                                                                               |
| |  |--05:NESTED LOOP JOIN [CROSS JOIN]                                             |
| |  |  |                                                                            |
| |  |  |--03:SINGULAR ROW SRC                                                       |
| |  |  |                                                                            |
| |  |  04:UNNEST [t2.field_32 t3]                                                   |
| |  |                                                                               |
| |  01:SCAN HDFS [random_nested_db_0.table_2 t2]                                    |
| |     partitions=1/1 files=1 size=18.09MB                                          |
| |                                                                                  |
| 00:SCAN HDFS [random_nested_db_0.table_1 t1]                                       |
|    partitions=1/1 files=1 size=4.15MB                                              |
+------------------------------------------------------------------------------------+

Equivalent query for flattened data:

SELECT 1
FROM table_1 t1
LEFT JOIN  table_2 t2 ON (t2.field_34_field_40) = (t1.field_17)
INNER JOIN LATERAL (
SELECT *
FROM table_2_field_32 t3
WHERE
(t2.id) = (t3.table_2_id)
) t3 ON True