Shulou(Shulou.com)06/01 Report--

Pt-online-schema-change dependency conditions:

The table of the operation must have a primary key, otherwise the execution will report an error

The experiments are as follows:

MySQL [mysql] > create database chenfeng

Query OK, 1 row affected (0.00 sec)

MySQL [mysql] > use chenfeng

Database changed

Create a table test with a primary key:

MySQL [chenfeng] > create table test

-> (id int (10) not null auto_increment

-> k int (10) not null default'0'

-> c char (120) not null default'

-> primary key (id))

-> engine=innodb default charset=utf8

Query OK, 0 rows affected (0.03 sec)

MySQL [chenfeng] > desc test

+-+ +

| | Field | Type | Null | Key | Default | Extra | |

+-+ +

| | id | int (10) | NO | PRI | NULL | auto_increment |

| | k | int (10) | NO | | 0 | |

| | c | char (120) | NO | |

+-+ +

3 rows in set (0.01sec)

MySQL [chenfeng] >

MySQL [chenfeng] > show create table test\ G

* * 1. Row *

Table: test

Create Table: CREATE TABLE `test` (

`id`int (10) NOT NULL AUTO_INCREMENT

`k`int (10) NOT NULL DEFAULT'0'

`c` char (120) NOT NULL DEFAULT''

PRIMARY KEY (`id`)

) ENGINE=InnoDB DEFAULT CHARSET=utf8

1 row in set (0.00 sec)

[root@chenfeng] # pt-online-schema-change-- alter= "modify c varchar not null default''"-- user=root-- password=123456 Drunchenfengle tasking test-- charset=utf8-- execute

No slaves found. See-- recursion-method if host chenfeng has slaves.

Not checking slave lag because no slaves were found and-- check-slave-lag was not specified.

Operation, tries, wait:

Analyze_table, 10, 1

Copy_rows, 10, 0.25

Create_triggers, 10, 1

Drop_triggers, 10, 1

Swap_tables, 10, 1

Update_foreign_keys, 10, 1

Altering `chenfeng`.`test`...

Creating new table...

Created new table chenfeng._test_new OK.

Altering new table...

Altered `chenfeng`.` _ test_ new` OK.

2016-10-07T18:57:36 Creating triggers...

2016-10-07T18:57:36 Created triggers OK.

2016-10-07T18:57:36 Copying approximately 1 rows...

2016-10-07T18:57:36 Copied rows OK.

2016-10-07T18:57:36 Analyzing new table...

2016-10-07T18:57:36 Swapping tables...

2016-10-07T18:57:36 Swapped original and new tables OK.

2016-10-07T18:57:36 Dropping old table...

2016-10-07T18:57:36 Dropped old table `chenfeng`.` _ test_ old` OK.

2016-10-07T18:57:36 Dropping triggers...

2016-10-07T18:57:36 Dropped triggers OK.

Successfully altered `chenfeng`.`test`.

[root@chenfeng ~] #

MySQL [(none)] > use chenfeng

Reading table information for completion of table and column names

You can turn off this feature to get a quicker startup with-A

Database changed

MySQL [chenfeng] > show tables

+-+

| | Tables_in_chenfeng |

+-+

| | test |

+-+

1 row in set (0.00 sec)

MySQL [chenfeng] > desc test

+-+ +

| | Field | Type | Null | Key | Default | Extra | |

+-+ +

| | id | int (10) | NO | PRI | NULL | auto_increment |

| | k | int (10) | NO | | 0 | |

| | c | varchar (150) | NO | |

+-+ +

3 rows in set (0.00 sec)

Varchar is the result we want.

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