Handling table column named default

Learn about the change to ensure that Hive is able to reference a table column that is named as 'default'.

Before upgrade to CDP 7.1.8

Hive was unable to reference table columns that are named as 'default' and returns NULL. For example,

create table t1 (a int, `default` int) stored as orc TBLPROPERTIES ('transactional'='true');
insert into t1 values (1, 2), (10, 11);
update t1 set a = `default`;
select * from t1;

Output:
NULL   NULL
NULL   NULL

Expected output:
2      2
11     11

After upgrade to 7.1.8

HIVE-25969 fixes this issue and Hive is now able to reference table columns named 'default'.