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drop table if exists t1;
CREATE TABLE t1 (data LONGBLOB) ENGINE=myisam;
INSERT INTO t1 (data) VALUES (NULL);
UPDATE t1 set data=repeat('a',18*1024*1024);
select length(data) from t1;
length(data)
18874368
delete from t1 where left(data,1)='a';
check table t1;
Table Op Msg_type Msg_text
test.t1 check status OK
truncate table t1;
INSERT INTO t1 (data) VALUES (repeat('a',1*1024*1024));
INSERT INTO t1 (data) VALUES (repeat('b',16*1024*1024-1024));
delete from t1 where left(data,1)='b';
check table t1;
Table Op Msg_type Msg_text
test.t1 check status OK
UPDATE t1 set data=repeat('c',17*1024*1024);
check table t1;
Table Op Msg_type Msg_text
test.t1 check status OK
delete from t1 where left(data,1)='c';
check table t1;
Table Op Msg_type Msg_text
test.t1 check status OK
INSERT INTO t1 set data=repeat('a',18*1024*1024);
select length(data) from t1;
length(data)
18874368
alter table t1 modify data blob;
select length(data) from t1;
length(data)
0
drop table t1;
CREATE TABLE t1 (data BLOB) ENGINE=myisam;
INSERT INTO t1 (data) VALUES (NULL);
UPDATE t1 set data=repeat('a',18*1024*1024);
Warnings:
Warning 1265 Data truncated for column 'data' at row 1
select length(data) from t1;
length(data)
65535
drop table t1;
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