create table t (a varchar(100)) engine=innodb;
select name, pos, mtype, prtype, len from information_schema.innodb_sys_columns where name='a';
name	pos	mtype	prtype	len
a	0	1	524303	100
alter table t modify a varchar(110), algorithm=inplace;
select name, pos, mtype, prtype, len from information_schema.innodb_sys_columns where name='a';
name	pos	mtype	prtype	len
a	0	1	524303	110
drop table t;