InnoDB engine of MySql index (clustered index)

Mysql internal file

Use InnoDB as the storage engine to create a table test_innodb

CREATE TABLE `test_innodb` (
  `ID` int(11) DEFAULT NULL,
  `NAME` varchar(99),
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

We will find two files in the D:\MySQL\mysql-5.7.13-winx64\data\ library name directory:

test_innodb.frm: data structure file

test_innodb.ibd: index and data files

Query process

When execute select * from test_my where id = 1

1.  Then read the leaf node with id=1 in test_innodb.frm; (the root node is located in Ram, so disk IO is required to perform two operations to obtain the leaf node with id=1)
2. Get all the data information in id=1 directly

Test_innodb.ibd file data structure