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Azure Database for MySQL 中的限制Limitations in Azure Database for MySQL

以下各部分介绍了数据库服务中的容量、存储引擎支持、特权支持、数据操作语句支持和功能限制。The following sections describe capacity, storage engine support, privilege support, data manipulation statement support, and functional limits in the database service. 另请参阅适用于 MySQL 数据库引擎的常规限制Also see general limitations applicable to the MySQL database engine.

最大连接数Maximum connections

每个定价层的最大连接数和 vCore 数如下所示:The maximum number of connections per pricing tier and vCores are as follows:

定价层Pricing Tier vCore(s)vCore(s) 最大连接数 Max Connections
基本Basic 1 5050
基本Basic 22 100100
常规用途General Purpose 22 300300
常规用途General Purpose 44 625625
常规用途General Purpose 88 12501250
常规用途General Purpose 1616 25002500
常规用途General Purpose 3232 50005000
常规用途General Purpose 6464 1000010000
内存优化Memory Optimized 22 600600
内存优化Memory Optimized 44 12501250
内存优化Memory Optimized 88 25002500
内存优化Memory Optimized 1616 50005000
内存优化Memory Optimized 3232 1000010000

当连接数超出限制时,可能会收到以下错误:When connections exceed the limit, you may receive the following error:

错误 1040 (08004):连接过多ERROR 1040 (08004): Too many connections

存储引擎支持Storage engine support

支持Supported

不支持Unsupported

特权支持Privilege support

不支持Unsupported

  • DBA 角色:许多服务器参数和设置可能会无意中导致服务器性能下降或使 DBMS 的 ACID 属性无效。DBA role: Many server parameters and settings can inadvertently degrade server performance or negate ACID properties of the DBMS. 因此,为了维护产品级别的服务完整性和 SLA,此服务不公开 DBA 角色。As such, to maintain the service integrity and SLA at a product level, this service does not expose the DBA role. 默认用户帐户(在创建新的数据库实例时构造)允许该用户执行托管数据库实例中的大部分 DDL 和 DML 语句。The default user account, which is constructed when a new database instance is created, allows that user to perform most of DDL and DML statements in the managed database instance.
  • SUPER 特权:SUPER 特权同样也受到限制。SUPER privilege: Similarly SUPER privilege is also restricted.
  • DEFINER:需要创建并限制超级权限。DEFINER: Requires super privileges to create and is restricted. 如果使用备份导入数据,请在执行 mysqldump 时手动删除或使用 --skip-definer 命令删除 CREATE DEFINER 命令。If importing data using a backup, remove the CREATE DEFINER commands manually or by using the --skip-definer command when performing a mysqldump.

数据操作语句支持Data manipulation statement support

支持Supported

  • 支持 LOAD DATA INFILE,但必须指定 [LOCAL] 参数,并将其定向到 UNC 路径(通过 SMB 装载的 Azure 存储空间)。LOAD DATA INFILE is supported, but the [LOCAL] parameter must be specified and directed to a UNC path (Azure storage mounted through SMB).

不支持Unsupported

  • SELECT ... INTO OUTFILE

功能限制Functional limitations

缩放操作Scale operations

  • 目前不支持向/从基本定价层动态缩放。Dynamic scaling to and from the Basic pricing tiers is currently not supported.
  • 不支持减小服务器存储大小。Decreasing server storage size is not supported.

服务器版本升级Server version upgrades

  • 目前不支持在主要数据库引擎版本之间进行自动迁移。Automated migration between major database engine versions is currently not supported. 如果要升级到下一主要版本,请将其转储和还原到使用新引擎版本创建的服务器。If you would like to upgrade to the next major version, take a dump and restore it to a server that was created with the new engine version.

时间点还原Point-in-time-restore

  • 使用 PITR 功能时,将使用与新服务器所基于的服务器相同的配置创建新服务器。When using the PITR feature, the new server is created with the same configurations as the server it is based on.
  • 不支持还原已删除的服务器。Restoring a deleted server is not supported.

VNet 服务终结点VNet service endpoints

  • 只有常规用途和内存优化服务器才支持 VNet 服务终结点。Support for VNet service endpoints is only for General Purpose and Memory Optimized servers.

存储大小Storage size

  • 有关每个定价层的存储大小限制,请参阅定价层Please refer to pricing tiers for the storage size limits per pricing tier.

当前已知的问题Current known issues

  • 建立连接后,MySQL 服务器实例显示错误的服务器版本。MySQL server instance displays the wrong server version after connection is established. 若要获取正确的服务器实例引擎版本,请使用 select version(); 命令。To get the correct server instance engine version, use the select version(); command.

后续步骤Next steps