[jira] [Created] (HIVE-9645) Constant folding case NULL equality

["Gopal V (JIRA)" <ji...@apache.org>]

Gopal V created HIVE-9645:
-----------------------------

             Summary: Constant folding case NULL equality
                 Key: HIVE-9645
                 URL: https://issues.apache.org/jira/browse/HIVE-9645
             Project: Hive
          Issue Type: Bug
          Components: Logical Optimizer
    Affects Versions: 1.2.0
            Reporter: Gopal V


Hive logical optimizer does not follow the Null scan codepath when encountering a NULL = 1;

NULL = 1 is not evaluated as false in the constant propogation implementation.

{code}
hive> explain select count(1) from store_sales where null=1;
...
             TableScan
                  alias: store_sales
                  filterExpr: (null = 1) (type: boolean)
                  Statistics: Num rows: 550076554 Data size: 49570324480 Basic stats: COMPLETE Column stats: COMPLETE
                  Filter Operator
                    predicate: (null = 1) (type: boolean)
                    Statistics: Num rows: 275038277 Data size: 0 Basic stats: PARTIAL Column stats: COMPLETE
{code}




--
This message was sent by Atlassian JIRA
(v6.3.4#6332)