why transaction seems not work?

[建伟 程]

Hi,

test evn:

1.the mysql (in fact is 5.5.50-MariaDB),
2.write five million records
3.one record size is 400 bytes.

test steps:
1. use the query("set autocommit=0") and query("commit") in the code,the result
write the 5 million records in the 11 minutes.

2. not use the transaction to write the 5 million recors by remove the query("set autocommit=0") and query("commit") in the code,the result still be 11 minutes;

why

Thank u
william