DROP DATABASE IF EXISTS `mcol_4758`;
CREATE DATABASE `mcol_4758`;
USE `mcol_4758`;
CREATE TABLE src (c0 INT, cLB LONGBLOB,  cLT LONGTEXT)engine=columnstore default charset utf8mb4;
SELECT column_name, data_type, column_length FROM information_schema.columnstore_columns WHERE hex(table_schema)=hex('mcol_4758') and hex(table_name)=hex('src');
column_name	data_type	column_length
c0	int	4
clb	blob	16777215
clt	text	16777215
INSERT INTO src VALUES (1, "Pretty Bloby Thing", "This is some text");
select * from src where c0=1 and substr(cLT, 1, 4)="This";
c0	cLB	cLT
1	Pretty Bloby Thing	This is some text
ALTER TABLE src ADD COLUMN (cLT2 LONGTEXT);
UPDATE src SET cLT2="My Friday Night" where c0=1;
select * from src where c0=1 and substr(cLT, 1, 4)="This";
c0	cLB	cLT	cLT2
1	Pretty Bloby Thing	This is some text	My Friday Night
DROP DATABASE `mcol_4758`;