PerconaOnlineSchemaChange component - PHP wrapper for Percona's pt-online-schema-change utility - designed to perform Alter table without table locks.

Using this component, you will need to write alter table on large tables in Yii migrations. You need to use non-transactional methods (up()/down()) as migration can run for a long time, and the transaction may timeout.

   public function up(){
        
      /**
      * @var $changer PerconaOnlineSchemaChange
      */
      $changer = \Yii::$app->perconaOnlineSchemaChange;
      try{
           $changer->run('tbl_order', 'ADD COLUMN test000 INT(10)',
            [
              'alterForeignKeysMethod' => $changer::ALTER_FOREIGN_KEY_DROP_SWAP,
              'execute' => true,
              'debug' => false
            ]);
            return true;
      } catch (RuntimeException $ex){
         echo $ex->getMessage() . PHP_EOL;
         return false;
      }
    }

execute - true - execute the script, false - check its correctness. The default is false.

debug - enable debug mode or not. The default is false.

alterForeignKeysMethod - how to change foreign keys to point to a new table. The default is 'drop_swap'.

Operations allowed to be performed and their features:

1. In each Yii migration through this component, only 1 table change operation should be performed.

2. Changes can only be made on tables containing a PRIMARY KEY.

3. Permitted operations: ADD COLUMN, DROP COLUMN, MODIFY COLUMN, ADD INDEX, DROP INDEX, ADD FOREIGN KEY, DROP FOREIGN KEY.

4. When adding a column with NOT NULL, you must specify the default value.

5. If we add a foreign key, for example with the name fk_foo, then in order to delete it through a rollback to down, you will need to refer to the key through an underscore:

 DROP FOREIGN KEY _fk_foo