Plz review.

4QA JOIN with wide DECIMAL key column leverages Typeless JOIN so JOINs with strings must be also tested. You could take this and this test as a reference of what had been tested so far.

This is not a bug dleeyh this is a new feature for 6.1.1. All tests that were mentioned can be references for QA.

Build verified: 6.2.1-1 ( #2921)

Tested in 6.1.1, 6.1.1 with columnstore_select_handler=off, 6.2.1
Tested inner, left, right joins, in, not in, exists, not exists
Tested with t1 being bigint and varchar(5);

#CASE 1

ColumnStore 6.1.1
Found this issue in 6.1.1

create table t1 (c1 bigint) engine=columnstore;
create table t2 (c1 decimal(38)) engine=columnstore;
insert into t1 values (1), (3), (5), (6), (NULL);
insert into t2 values (1), (2), (3), (4), (5), (NULL);
select * from t1 where c1 not in (select c1 from t2);

Columnstore tables, returned 6
Columnstore tables, columnstore_select_handler=off; returned empty set
Innodb tables, returned empty set

ColumnStore 6.2.1
The issue has been corrected in 6.2.1

#CASE 2
ColumnStore 6.1.1
Found this issue in 6.1.1

create table t1 (c1 varchar(5)) engine=columnstore;
create table t2 (c1 decimal(38)) engine=columnstore;
create table t3 (c1 decimal(38)) engine=columnstore;
#

1. varchar(5), decimal(38)
   #
   #INNER JOIN
   insert into t1 values ('1'), ('2'), ('3'), ('4'), ('5');
   insert into t2 values (1), (2), (3), (4), (5);
   insert into t3 values (1), (2), (3), (4), (5);
   select *
   from t1
   inner join t2 on t1.c1=t2.c1
   inner join t3 on t1.c1=t3.c1;

MariaDB [mytest]> select *
-> from t1
-> inner join t2 on t1.c1=t2.c1
-> inner join t3 on t1.c1=t3.c1;
ERROR 1815 (HY000): Internal error: IDB-1002: 't1' and 't3' have incompatible column type specified for join condition.

The issue has been corrected in 6.2.1

dleeyh
Case 1 The join must return a record 6 with select_handler.
Case 2 The join implementation in MCS is never supposed to work for joins on varchar(5) to decimal(38) columns.