[IMPALA-8848] Cardinality of UnionNode does not handle missing input cardinality correctly

• Type: Bug
• Status: Resolved
• Priority: Critical
• Resolution: Fixed
• Affects Version/s: Impala 3.3.0
• Fix Version/s: Impala 3.3.0
• Component/s: Frontend
• Labels: planner
• Target Version: Impala 3.3.0
• Epic Color: ghx-label-3
• Assignee: Tim Armstrong
• Reporter: Tim Armstrong
• Created: 08/Aug/19 18:33
• Updated: 12/Aug/19 15:43
• Resolved: 12/Aug/19 15:43

Description

|  35:UNION
|  |  mem-estimate=0B mem-reservation=0B thread-reservation=0
|  |  tuple-ids=82 row-size=28B cardinality=0
|  |  in pipelines: 75(GETNEXT)
|  |
|  75:AGGREGATE [FINALIZE]
|  |  output: sum:merge((((ws_ext_list_price - ws_ext_wholesale_cost - ws_ext_discount_amt) + ws_ext_sales_price) / 2))
|  |  group by: c_customer_id, c_first_name, c_last_name, c_preferred_cust_flag, c_birth_country, c_login, c_email_address, d_year
|  |  mem-estimate=128.00MB mem-reservation=34.00MB spill-buffer=2.00MB thread-reservation=0
|  |  tuple-ids=81 row-size=104B cardinality=unavailable
|  |  in pipelines: 75(GETNEXT), 36(OPEN)

I expect that the cardinality should be unavailable, not 0.