[IMPALA-831] Aggregation on union inside (inline) view not distributed properly.

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: Impala 1.2.3
• Fix Version/s: Impala 1.3
• Assignee: Alexander Behm
• Reporter: Alexander Behm
• Created: 25/Feb/14 01:49
• Updated: 13/Mar/14 16:09
• Resolved: 13/Mar/14 16:09

Description

The count of the following query is executed entirely by the coordinator.

[localhost:21000] > explain select count(*) from (select * from functional.alltypes union all select * from functional.alltypessmall) t;
Query: explain select count(*) from (select * from functional.alltypes union all select * from functional.alltypessmall) t
+-----------------------------------------------------------+
| Explain String                                            |
+-----------------------------------------------------------+
| Estimated Per-Host Requirements: Memory=192.00MB VCores=2 |
|                                                           |
| 03:AGGREGATE [FINALIZE]                                   |
| |  output: count(*)                                       |
| |                                                         |
| 04:EXCHANGE [PARTITION=UNPARTITIONED]                     |
| |                                                         |
| |--06:MERGE                                               |
| |  |                                                      |
| |  02:SCAN HDFS [functional.alltypessmall]                |
| |     partitions=4/4 size=12.64KB                         |
| |                                                         |
| 05:MERGE                                                  |
| |                                                         |
| 01:SCAN HDFS [functional.alltypes]                        |
|    partitions=24/24 size=956.90KB                         |
+-----------------------------------------------------------+