《MySQL系列-InnoDB引擎26》表-InnoDB行记录格式

Posted 2023-03-10 DATA数据猿

InnoDB行记录格式

  InnoDB存储引擎和大多数数据库意义(如Oracle和Micrisoft SQL Server数据库)，记录是以行的形式存储的。这意味着页中保存着表中一行行的数据。InnoDB存储引擎设计了4种不同类型的行格式，分别是Compact,Redundant,Dynamic,Compressed行格式。

  可以通过命令select @@innodb_default_row_format;查看默认的行格式：

mysql> select @@innodb_default_row_format;
+-----------------------------+
| @@innodb_default_row_format |
+-----------------------------+
| dynamic                     |
+-----------------------------+
1 row in set (0.00 sec)

  也可以查看当前某表的行格式：

# 可以看到ROW_format行是Dynamic
mysql> show table status like 'zxy'\\G;
*************************** 1. row ***************************
           Name: zxy
         Engine: InnoDB
        Version: 10
     Row_format: Dynamic
           Rows: 12
 Avg_row_length: 1365
    Data_length: 16384
Max_data_length: 0
   Index_length: 0
      Data_free: 0
 Auto_increment: NULL
    Create_time: 2022-10-08 16:51:21
    Update_time: 2023-02-08 09:55:59
     Check_time: NULL
      Collation: latin1_swedish_ci
       Checksum: NULL
 Create_options:
        Comment:
1 row in set (0.00 sec)

  也可以修改表的行格式：

# 1.将表的行格式修改为compact
mysql> alter table zxy row_format=compact;
Query OK, 0 rows affected (0.12 sec)
Records: 0  Duplicates: 0  Warnings: 0

# 2.查看zxy表的存储格式，ROW_format是Compact
mysql> show table status like 'zxy'\\G;
*************************** 1. row ***************************
           Name: zxy
         Engine: InnoDB
        Version: 10
     Row_format: Compact
           Rows: 12
 Avg_row_length: 1365
    Data_length: 16384
Max_data_length: 0
   Index_length: 0
      Data_free: 0
 Auto_increment: NULL
    Create_time: 2023-02-24 09:43:32
    Update_time: NULL
     Check_time: NULL
      Collation: latin1_swedish_ci
       Checksum: NULL
 Create_options: row_format=COMPACT
        Comment:
1 row in set (0.00 sec)

ERROR:
No query specified