[IMPALA-11200] Redundant additions to ExecOption field in query profile of grouping aggregator node when inside a subplan

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: Impala 4.1.0
• Epic Color: ghx-label-10
• Assignee: Csaba Ringhofer
• Reporter: Bikramjeet Vig
• Created: 25/Mar/22 01:13
• Updated: 13/Jun/23 07:06
• Resolved: 13/Apr/22 15:38

Description

There is an excessive addition of "Codegen Enabled" text to "ExecOption" field in the query profile when a grouping agg is a part of a subplan that is created to unnest a complex type.
I was able to reproduce this using one of the queries we used for end to end testing:

use tpch_nested_parquet;
select c_custkey, v.* from customer c,
  (select o_orderpriority, count(o_orderkey) c, sum(o_totalprice) s,
          avg(o_totalprice) a, max(o_orderstatus) mx,
          min(o_orderdate) mn
   from c.c_orders
   group by o_orderpriority) v
where c_custkey < 4;

From the query profile:

     AGGREGATION_NODE (id=4):
             - InactiveTotalTime: 0.000ns
             - PeakMemoryUsage: 36.04 MB (37794944)
             - RowsReturned: 0 (0)
             - RowsReturnedRate: 0
             - TotalTime: 1.571ms
            GroupingAggregator 0:
              ExecOption: Codegen Enabled, Codegen Enabled, Codegen Enabled       <== THIS PART!
               - BuildTime: 68.253us
               - GetResultsTime: 72.634us

The reason this happens is because "Codegen Enabled" is added to the ExecOption everytime the agg node is Opened as a result of the subplan being called again and again to unnest.

Issue Links

• is related to: IMPALA-12204 Redundant codegen info of HashJoinBuilder inside a subplan
• relates to: IMPALA-11860 Query failure due to large buffer allocation provides insufficient context