A simple scenario isn't deterministic. It occasionally fails to return a row with the last select b/c INSERT..SELECT lacks atomicity thus there is a small delay b/w time A when INSERT..SELECT returns and time B when records become available.

CREATE DATABASE mcs25_db;

USE mcs25_db;

CREATE TABLE t_cs(

c1 INT,

c2 INT

)ENGINE=Columnstore;

CREATE TABLE t_myisam(

c1 INT,

c2 INT

)ENGINE=MyISAM;

INSERT INTO t_cs SELECT * FROM t_myisam;

SELECT * FROM t_cs;