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create table t (a int NOT NULL) engine=innodb row_format= compressed;
alter table t modify a int NULL, algorithm=instant;
ERROR 0A000: ALGORITHM=INSTANT is not supported for this operation. Try ALGORITHM=INPLACE
drop table t;
create table t (a int NOT NULL) engine=innodb row_format= dynamic;
alter table t modify a int NULL, algorithm=instant;
ERROR 0A000: ALGORITHM=INSTANT is not supported for this operation. Try ALGORITHM=INPLACE
drop table t;
create table t (a int NOT NULL) engine=innodb row_format= compact;
alter table t modify a int NULL, algorithm=instant;
ERROR 0A000: ALGORITHM=INSTANT is not supported for this operation. Try ALGORITHM=INPLACE
drop table t;
create table t (
id int primary key,
a int NOT NULL default 0,
b int NOT NULL default 0,
c int NOT NULL default 0,
index idx (a,b,c)
) engine=innodb row_format=redundant;
insert into t (id, a) values (0, NULL);
ERROR 23000: Column 'a' cannot be null
insert into t (id, b) values (0, NULL);
ERROR 23000: Column 'b' cannot be null
insert into t (id, c) values (0, NULL);
ERROR 23000: Column 'c' cannot be null
insert into t values (1,1,1,1);
set @id = (select table_id from information_schema.innodb_sys_tables
where name = 'test/t');
select * from information_schema.innodb_sys_columns where table_id=@id;
TABLE_ID NAME POS MTYPE PRTYPE LEN
TABLE_ID id 0 6 1283 4
TABLE_ID a 1 6 1283 4
TABLE_ID b 2 6 1283 4
TABLE_ID c 3 6 1283 4
alter table t modify a int NULL, algorithm=instant;
insert into t values (2, NULL, 2, 2);
alter table t modify b int NULL, algorithm=nocopy;
insert into t values (3, NULL, NULL, 3);
alter table t modify c int NULL, algorithm=inplace;
insert into t values (4, NULL, NULL, NULL);
select * from information_schema.innodb_sys_columns where table_id=@id;
TABLE_ID NAME POS MTYPE PRTYPE LEN
TABLE_ID id 0 6 1283 4
TABLE_ID a 1 6 1027 4
TABLE_ID b 2 6 1027 4
TABLE_ID c 3 6 1027 4
select * from t;
id a b c
4 NULL NULL NULL
3 NULL NULL 3
2 NULL 2 2
1 1 1 1
check table t;
Table Op Msg_type Msg_text
test.t check status OK
drop table t;
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