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缩短物理迁移到 Amazon Aurora MySQL 的时间

您可以进行以下数据库修改，以加快将数据库迁移到 Amazon Aurora MySQL 的过程。

不支持的表类型

Aurora MySQL 仅支持用于数据库表的 InnoDB 引擎。如果您的数据库中有 MyISAM 表，则必须先转换这些表，然后才能迁移到 Aurora MySQL 中。迁移过程中，转换过程需要额外的空间以便将 MyISAM 转换为 InnoDB。

若要降低空间用尽的可能性或加快迁移过程，请先将所有 MyISAM 表转换为 InnoDB 表，然后再迁移这些表。生成的 InnoDB 表的大小与 Aurora MySQL 要求该表具有的大小相同。要将 MyISAM 表转换为 InnoDB 表，请运行以下命令：

ALTER TABLE schema.table_name engine=innodb, algorithm=copy;

Aurora MySQL 不支持压缩的表或页（即，使用 ROW_FORMAT=COMPRESSED 或 COMPRESSION = {"zlib"|"lz4"} 创建的表）。

为了避免用完空间或为了加速迁移过程，请通过将 ROW_FORMAT 设置为 DEFAULT、COMPACT、DYNAMIC 或 REDUNDANT 来扩展您的压缩表。对于压缩的页，请设置 COMPRESSION="none"。

有关更多信息，请参阅 MySQL 文档中的 InnoDB 行格式和 InnoDB 表和页压缩。

您可以在现有 MySQL 数据库实例上使用以下 SQL 脚本来列出数据库中属于 MyISAM 表或压缩表的表。

-- This script examines a MySQL database for conditions that block
-- migrating the database into Aurora MySQL.
-- It must be run from an account that has read permission for the
-- INFORMATION_SCHEMA database.

-- Verify that this is a supported version of MySQL.

select msg as `==> Checking current version of MySQL.`
from
  (
  select
    'This script should be run on MySQL version 5.6 or higher. ' +
    'Earlier versions are not supported.' as msg,
    cast(substring_index(version(), '.', 1) as unsigned) * 100 +
      cast(substring_index(substring_index(version(), '.', 2), '.', -1)
      as unsigned)
    as major_minor
  ) as T
where major_minor <> 506;


-- List MyISAM and compressed tables. Include the table size.

select concat(TABLE_SCHEMA, '.', TABLE_NAME) as `==> MyISAM or Compressed Tables`,
round(((data_length + index_length) / 1024 / 1024), 2) "Approx size (MB)"
from INFORMATION_SCHEMA.TABLES
where
  ENGINE <> 'InnoDB'
  and
  (
    -- User tables
    TABLE_SCHEMA not in ('mysql', 'performance_schema',
                         'information_schema')
    or
    -- Non-standard system tables
    (
      TABLE_SCHEMA = 'mysql' and TABLE_NAME not in
        (
          'columns_priv', 'db', 'event', 'func', 'general_log',
          'help_category', 'help_keyword', 'help_relation',
          'help_topic', 'host', 'ndb_binlog_index', 'plugin',
          'proc', 'procs_priv', 'proxies_priv', 'servers', 'slow_log',
          'tables_priv', 'time_zone', 'time_zone_leap_second',
          'time_zone_name', 'time_zone_transition',
          'time_zone_transition_type', 'user'
        )
    )
  )
  or
  (
    -- Compressed tables
       ROW_FORMAT = 'Compressed'
  );

具有不支持的权限的用户账户

如果用户账户的权限不受 Aurora MySQL 支持，则在导入这些账户时将不包含这些不受支持的权限。有关支持的权限列表，请参阅基于角色的权限模型。

可以在源数据库上运行以下 SQL 查询，以列出具有不受支持的权限的用户账户。

SELECT
    user,
    host
FROM
    mysql.user
WHERE
    Shutdown_priv = 'y'
    OR File_priv = 'y'
    OR Super_priv = 'y'
    OR Create_tablespace_priv = 'y';

Aurora MySQL 版本 3 中的动态权限

不会导入动态权限。Aurora MySQL 版本 3 支持以下动态权限。

'APPLICATION_PASSWORD_ADMIN',
'CONNECTION_ADMIN',
'REPLICATION_APPLIER',
'ROLE_ADMIN',
'SESSION_VARIABLES_ADMIN',
'SET_USER_ID',
'XA_RECOVER_ADMIN'

以下示例脚本向 Aurora MySQL 数据库集群中的用户账户授予支持的动态权限。

-- This script finds the user accounts that have Aurora MySQL supported dynamic privileges 
-- and grants them to corresponding user accounts in the Aurora MySQL DB cluster.

/home/ec2-user/opt/mysql/8.0.26/bin/mysql -uusername -pxxxxx -P8026 -h127.0.0.1 -BNe "SELECT
  CONCAT('GRANT ', GRANTS, ' ON *.* TO ', GRANTEE ,';') AS grant_statement
  FROM (select GRANTEE, group_concat(privilege_type) AS GRANTS FROM information_schema.user_privileges 
      WHERE privilege_type IN (
        'APPLICATION_PASSWORD_ADMIN',
        'CONNECTION_ADMIN',
        'REPLICATION_APPLIER',
        'ROLE_ADMIN',
        'SESSION_VARIABLES_ADMIN',
        'SET_USER_ID',
        'XA_RECOVER_ADMIN')
      AND GRANTEE NOT IN (\"'mysql.session'@'localhost'\",\"'mysql.infoschema'@'localhost'\",\"'mysql.sys'@'localhost'\") GROUP BY GRANTEE)
      AS PRIVGRANTS; " | /home/ec2-user/opt/mysql/8.0.26/bin/mysql -u master_username -p master_password -h DB_cluster_endpoint

以 'rdsadmin'@'localhost' 作为定义程序的存储对象

不会导入以 'rdsadmin'@'localhost' 作为定义程序的函数、过程、视图、事件和触发器。

您可以在源 MySQL 数据库上使用以下 SQL 脚本来列出具有不受支持的定义程序的存储对象。

-- This SQL query lists routines with `rdsadmin`@`localhost` as the definer.

SELECT
    ROUTINE_SCHEMA,
    ROUTINE_NAME
FROM
    information_schema.routines
WHERE
    definer = 'rdsadmin@localhost';

-- This SQL query lists triggers with `rdsadmin`@`localhost` as the definer.

SELECT
    TRIGGER_SCHEMA,
    TRIGGER_NAME,
    DEFINER
FROM
    information_schema.triggers
WHERE
    DEFINER = 'rdsadmin@localhost';

-- This SQL query lists events with `rdsadmin`@`localhost` as the definer.

SELECT
    EVENT_SCHEMA,
    EVENT_NAME
FROM
    information_schema.events
WHERE
    DEFINER = 'rdsadmin@localhost';

-- This SQL query lists views with `rdsadmin`@`localhost` as the definer.
SELECT
    TABLE_SCHEMA,
    TABLE_NAME
FROM
    information_schema.views
WHERE
    DEFINER = 'rdsadmin@localhost';