[KUDU-1106] Impala pushdown for comparison vs constant expression not working

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: Private Beta
• Component/s: impala, perf
• Target Version/s: Public beta
• Assignee: David Alves
• Reporter: Todd Lipcon
• Created: 03/Sep/15 12:07
• Updated: 16/Sep/15 19:07
• Resolved: 16/Sep/15 19:07

Description

Query: explain select host, metric, avg(value), count(*) from metrics where host = 've0504.halxg.cloudera.com' and `timestamp` >= unix_timestamp(now() + interval 7 hours - interval 60 seconds)  group by host, metric
+----------------------------------------------------------------------------------------------+
| Explain String                                                                               |
+----------------------------------------------------------------------------------------------+
| Estimated Per-Host Requirements: Memory=256.00MB VCores=2                                    |
| WARNING: The following tables are missing relevant table and/or column statistics.           |
| default.metrics                                                                              |
|                                                                                              |
| 04:EXCHANGE [UNPARTITIONED]                                                                  |
| |                                                                                            |
| 03:AGGREGATE [FINALIZE]                                                                      |
| |  output: avg:merge(value), count:merge(*)                                                  |
| |  group by: host, metric                                                                    |
| |                                                                                            |
| 02:EXCHANGE [HASH(host,metric)]                                                              |
| |                                                                                            |
| 01:AGGREGATE                                                                                 |
| |  output: avg(value), count(*)                                                              |
| |  group by: host, metric                                                                    |
| |                                                                                            |
| 00:SCAN KUDU [default.metrics]                                                               |
|    predicates: `timestamp` >= unix_timestamp(now() + INTERVAL 7 hours - INTERVAL 60 seconds) |
|    kudu predicates: host = 've0504.halxg.cloudera.com'                                       |
+----------------------------------------------------------------------------------------------+
Fetched 19 row(s) in 0.06s

I would have expected the timestamp predicate to be pushed, since the expression is a comparison vs constant expression.