[IMPALA-8184] Add timestamp validation to Orc scanner

• Type: Bug
• Status: Resolved
• Priority: Critical
• Resolution: Fixed
• Component/s: Backend
• Epic Link: Basic ORC Support
• Epic Color: ghx-label-8
• Assignee: Csaba Ringhofer
• Reporter: Csaba Ringhofer
• Created: 11/Feb/19 18:21
• Updated: 14/Feb/20 13:41
• Resolved: 14/Feb/20 13:41

Description

Similarly to Parquet, Orc can also contain timestamps that are not valid in Impala, e.g. Hive can insert timestamps before 1400 while these are invalid in Impala. These invalid timestamps are often handled similarly to NULL, bur are actually not "real" NULLs, which can lead to some some weird behavior:

Hive:
create table orcts (ts timestamp) stored as orc;
insert into orcts values ("1200-01-01");

Impala:
select * from orcts where ts is not null;
Returns 1 row:
NULL