[HIVE-24122] When CBO is enable, CAST(STR as Bigint)IS NOT NULL result is wrong

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Not A Problem
• Affects Version/s: 3.1.0, 3.1.2
• Fix Version/s: 4.0.0-alpha-2
• Component/s: CBO
• Assignee: GuangMing Lu
• Reporter: GuangMing Lu
• Created: 07/Sep/20 13:59
• Updated: 16/Nov/22 13:50
• Resolved: 21/Sep/20 12:49

Description

create  database testdb;
CREATE TABLE IF NOT EXISTS testdb.z_tab 
( 
    SEARCHWORD    STRING, 
    COUNT_NUM     BIGINT, 
    WORDS         STRING 
) 
ROW FORMAT DELIMITED FIELDS TERMINATED BY ',' 
STORED AS TEXTFILE;
insert into table testdb.z_tab values('hivetest',111,'aaa'),('hivetest2',111,'bbb');

set hive.cbo.enable=true;

SELECT CAST(searchword as bigint) IS NOT NULL FROM testdb.z_tab;
SELECT CAST(searchword as bigint) IS NULL FROM testdb.z_tab;

The SQL results for both queries are the same， as follows:

+-------+
|  _c0  |
+-------+
| true  |
| true  |
+-------+

SELECT CAST(searchword as bigint) IS NOT NULL FROM testdb.z_tab;  execute result is wrong