For QA:
Not much to test, UPDATEs should be slightly quicker. More a regression test.

Build verified: a build made on May 8 (Forgot to keep commit numbers)

The ticket passed regression test.

More test results. 1.2.4-1 is much slower then 1.2.3-1.

Reopening the ticket for development to look into it.

1.2.3-1

Welcome to the MariaDB monitor. Commands end with ; or \g.
Your MariaDB connection id is 17
Server version: 10.3.13-MariaDB-log Columnstore 1.2.3-1

Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

MariaDB [(none)]> use tpch10
Database changed
MariaDB [tpch10]> update lineitem set l_comment = "this is a test";
Query OK, 59986052 rows affected (1 min 13.344 sec)
Rows matched: 0 Changed: 0 Warnings: 0

1.2.4-1

[root@localhost ~]# mcsmysql
Welcome to the MariaDB monitor. Commands end with ; or \g.
Your MariaDB connection id is 16
Server version: 10.3.13-MariaDB-debug-log Columnstore 1.2.4-1

Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

MariaDB [(none)]> use tpch10
Database changed
MariaDB [tpch10]> update lineitem set l_comment = "this is a test";
Query OK, 59986052 rows affected (2 min 0.509 sec)
Rows matched: 0 Changed: 0 Warnings: 0

Further performance issues should be tracked in another ticket. This is just to test that the contributed commit does not cause a regression. The commit would not cause what you observed.

Created MCOL-3301 to track this DML performance issue.