MYSQL 索引页 结构图

create table t( a int(11) not null auto_increment,b char(3) default null,primary key(a));

mysql> select * from t;
+----+------+
| a  | b    |
+----+------+
|  1 | aaa  |
|  2 | bbb  |
|  3 | ccc  |
|  4 | ddd  |
|  5 | eee  |
|  6 | fff  |
|  7 | ggg  |
|  8 | hhh  |
|  9 | iii  |
| 10 | jjj  |
+----+------+
10 rows in set (0.00 sec)

hexdump -C t.ibd

锁结构与索引页对比

RECORD LOCKS space id 142 page no 3 n bits 80 index `PRIMARY` of table `test`.`t` trx id 31785 lock_mode X
Record lock, heap no 1 PHYSICAL RECORD: n_fields 1; compact format; info bits 0
 0: len 8; hex 73757072656d756d; asc supremum;;

Record lock, heap no 2 PHYSICAL RECORD: n_fields 4; compact format; info bits 0
 0: len 4; hex 80000001; asc     ;;
 1: len 6; hex 000000007c12; asc     | ;;
 2: len 7; hex 8f000001460110; asc     F  ;;
 3: len 3; hex 616161; asc aaa;;

Record lock, heap no 3 PHYSICAL RECORD: n_fields 4; compact format; info bits 0
 0: len 4; hex 80000002; asc     ;;
 1: len 6; hex 000000007c13; asc     | ;;
 2: len 7; hex 90000001b70110; asc        ;;
 3: len 3; hex 626262; asc bbb;;

Record lock, heap no 4 PHYSICAL RECORD: n_fields 4; compact format; info bits 0
 0: len 4; hex 80000003; asc     ;;
 1: len 6; hex 000000007c18; asc     | ;;
 2: len 7; hex 93000001b80110; asc        ;;
 3: len 3; hex 636363; asc ccc;;

Record lock, heap no 5 PHYSICAL RECORD: n_fields 4; compact format; info bits 0
 0: len 4; hex 80000004; asc     ;;
 1: len 6; hex 000000007c19; asc     | ;;
 2: len 7; hex 940000020a0110; asc        ;;
 3: len 3; hex 646464; asc ddd;;

Record lock, heap no 6 PHYSICAL RECORD: n_fields 4; compact format; info bits 0
 0: len 4; hex 80000005; asc     ;;
 1: len 6; hex 000000007c1a; asc     | ;;
 2: len 7; hex 950000014b0110; asc     K  ;;
 3: len 3; hex 656565; asc eee;;

Record lock, heap no 7 PHYSICAL RECORD: n_fields 4; compact format; info bits 0
 0: len 4; hex 80000006; asc     ;;
 1: len 6; hex 000000007c1b; asc     | ;;
 2: len 7; hex 960000014c0110; asc     L  ;;
 3: len 3; hex 666666; asc fff;;

Record lock, heap no 8 PHYSICAL RECORD: n_fields 4; compact format; info bits 0
 0: len 4; hex 80000007; asc     ;;
 1: len 6; hex 000000007c20; asc     | ;;
 2: len 7; hex 99000001a10110; asc        ;;
 3: len 3; hex 676767; asc ggg;;

Record lock, heap no 9 PHYSICAL RECORD: n_fields 4; compact format; info bits 0
 0: len 4; hex 80000008; asc     ;;
 1: len 6; hex 000000007c21; asc     |!;;
 2: len 7; hex 9a0000014f0110; asc     O  ;;
 3: len 3; hex 686868; asc hhh;;

Record lock, heap no 10 PHYSICAL RECORD: n_fields 4; compact format; info bits 0
 0: len 4; hex 80000009; asc     ;;
 1: len 6; hex 000000007c22; asc     |";;
 2: len 7; hex 9b000001500110; asc     P  ;;
 3: len 3; hex 696969; asc iii;;

Record lock, heap no 11 PHYSICAL RECORD: n_fields 4; compact format; info bits 0
 0: len 4; hex 8000000a; asc     ;;
 1: len 6; hex 000000007c23; asc     |#;;
 2: len 7; hex 9c000001a40110; asc        ;;
 3: len 3; hex 6a6a6a; asc jjj;;