[IMPALA-6276] incorrect projection of null column in hbase

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Duplicate
• Labels: correctness
• Epic Color: ghx-label-9
• Assignee: Unassigned
• Reporter: Vuk Ercegovac
• Created: 05/Dec/17 19:37
• Updated: 30/Oct/18 18:26
• Resolved: 30/Oct/18 18:26

Description

– All rows
select * from functional_hbase.nulltable;
a,,b,c,d,e,f,g
a,,NULL,NULL,NULL,ab,

– All rows that satisfy a predicate
select * from functional_hbase.nulltable where a = 'a';
a,,b,c,d,e,f,g
a,,NULL,NULL,NULL,ab,

– A null column of the results that satisfy the predicate.
select d from functional_hbase.nulltable where a = 'a';
No Results

Regardless of whether the predicate is pushed down to hbase, we still get no results.
(force no push by using a complex predicate, e.g., "like")

The row that satisfies the predicate has been materialized (see the "*" example) so
projecting d, regardless of its null or not, should yield one record and not an empty result set.

Against a non-hbase table:
select d from functional.nulltable where a = 'a';
a,,b,c,d,e,f,g
a,,NULL,NULL,NULL,ab,

Issue Links

• duplicates: IMPALA-283 select count(*) produces inconsistent results for hbase tables because of NULL projection
• relates to: IMPALA-283 select count(*) produces inconsistent results for hbase tables because of NULL projection
• relates to: IMPALA-728 HBase: NULL values not taken into account depending on the columns in SELECT