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}
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