[IMPALA-13273] Inconsistent handling of NOT NULL fields in iceberg tables

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: Impala 4.4.0
• Component/s: Frontend
• Labels: impala-iceberg
• Epic Color: ghx-label-7
• Assignee: Unassigned
• Reporter: Aleksey
• Created: 04/Aug/24 20:03
• Updated: 04/Aug/24 20:03

Description

Since IMPALA-12729 has been introduced, the following scenario occurs:

 

-- step 1 - create iceberg table without pk, but with not null
create table t_ice_constr(c1 int not null) stored as iceberg;
-- step 2 - insert success, parquet file contains null
insert into t_ice_constr select null;
-- step 3 - select returns 0
select c1 from t_ice_constr;
-- step 4 - select returns no rows
select c1 from t_ice_constr where c1 = 0;
-- step 5 - select return no rows
select c1 from t_ice_constr where c1 is null;

 

It seems to be an inconsistency here. Expected results - either 1 row on step 4, or null in step 3 and 1 row on step 5.
This behavior is supposedly caused by this change: https://github.com/apache/impala/commit/73171cb7164573349bd53a996a51bb7058b778e0#diff-adcc0990c7301e45752d00f6d8e65b192bfadffe179056037a7e14aff8718856R180