「適用於 MySQL 的 Azure 資料庫」中的限制Limitations in Azure Database for MySQL

下列各節說明資料庫服務中的容量、儲存引擎支援、權限支援、資料操作陳述式支援,以及功能限制。The following sections describe capacity, storage engine support, privilege support, data manipulation statement support, and functional limits in the database service. 另請參閱適用於 MySQL 資料庫引擎的一般限制 (英文)。Also see general limitations applicable to the MySQL database engine.

伺服器參數Server parameters

注意

如果您要尋找伺服器參數的最小值/最大值(如 max_connectionsinnodb_buffer_pool_size ),這些資訊已移至 伺服器參數 文章。If you are looking for min/max values for server parameters like max_connections and innodb_buffer_pool_size, this information has moved to the server parameters article.

適用於 MySQL 的 Azure 資料庫支援調整伺服器參數的值。Azure Database for MySQL supports tuning the values of server parameters. 某些參數的最小值和最大值 (例如。The min and max value of some parameters (ex. max_connectionsjoin_buffer_size query_cache_size) 是由伺服器的定價層和虛擬核心所決定。max_connections, join_buffer_size, query_cache_size) is determined by the pricing tier and vCores of the server. 如需這些限制的詳細資訊,請參閱 伺服器參數Refer to server parameters for more information about these limits.

在初始部署時,適用于 MySQL 的 Azure 伺服器會包含適用于時區資訊的系統資料表,但不會填入這些資料表。Upon initial deployment, an Azure for MySQL server includes systems tables for time zone information, but these tables are not populated. 時區資料表可藉由從 MySQL 命令列或 MySQL Workbench 等工具呼叫 mysql.az_load_timezone 預存程序來填入。The time zone tables can be populated by calling the mysql.az_load_timezone stored procedure from a tool like the MySQL command line or MySQL Workbench. 請參閱 Azure 入口網站Azure CLI 文章,以了解如何呼叫預存程序,以及設定全域或工作階段層級的時區。Refer to the Azure portal or Azure CLI articles for how to call the stored procedure and set the global or session-level time zones.

服務不支援密碼外掛程式,例如 "validate_password" 和 "caching_sha2_password"。Password plugins such as "validate_password" and "caching_sha2_password" are not supported by the service.

儲存引擎Storage engines

MySQL 支援許多儲存引擎。MySQL supports many storage engines. 在適用於 MySQL 的 Azure 資料庫上,支援和不支援下列儲存引擎:On Azure Database for MySQL, the following storage engines are supported and unsupported:

支援Supported

不支援Unsupported

& 資料操作支援的許可權Privileges & data manipulation support

許多伺服器參數與設定可能會不慎降低伺服器效能或使 MySQL 伺服器的 ACID 屬性變差。Many server parameters and settings can inadvertently degrade server performance or negate ACID properties of the MySQL server. 為了維護產品層級的服務完整性與 SLA,此服務不會公開多個角色。To maintain the service integrity and SLA at a product level, this service does not expose multiple roles.

MySQL 服務不允許直接存取基礎檔案系統。The MySQL service does not allow direct access to the underlying file system. 不支援某些資料操作命令。Some data manipulation commands are not supported.

不支援Unsupported

以下是不支援的:The following are unsupported:

  • DBA 角色:受限制。DBA role: Restricted. 或者,您可以使用在新的伺服器建立期間建立的系統管理員使用者 () ,讓您可以執行大部分的 DDL 和 DML 語句。Alternatively, you can use the administrator user (created during new server creation), allows you to perform most of DDL and DML statements.
  • 超級許可權:同樣地, 超級許可權 受到限制。SUPER privilege: Similarly, SUPER privilege is restricted.
  • 定義:需要進階的權限才能建立,而且受限制。DEFINER: Requires super privileges to create and is restricted. 如果使用備份匯入資料,執行 mysqldump 時以手動方式或使用 --skip-definer 命令移除 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.
  • 系統資料庫: mysql 系統資料庫 是唯讀的,用來支援各種 PaaS 功能。System databases: The mysql system database is read-only and used to support various PaaS functionality. 您無法對 mysql 系統資料庫進行變更。You cannot make changes to the mysql system database.
  • SELECT ... INTO OUTFILE:服務中不支援。SELECT ... INTO OUTFILE: Not supported in the service.
  • LOAD_FILE(file_name):服務中不支援。LOAD_FILE(file_name): Not supported in the service.

支援Supported

  • 支援 LOAD DATA INFILE,但必須指定 [LOCAL] 參數並導向至 UNC 路徑 (透過 SMB 掛接的 Azure 儲存體)。LOAD DATA INFILE is supported, but the [LOCAL] parameter must be specified and directed to a UNC path (Azure storage mounted through SMB).

功能限制:Functional limitations

調整作業Scale operations

  • 目前不支援基本定價層的雙向動態調整。Dynamic scaling to and from the Basic pricing tiers is currently not supported.
  • 不支援減少伺服器儲存體大小。Decreasing server storage size is not supported.

伺服器版本升級Server version upgrades

  • 目前不支援在主要資料庫引擎版本之間進行自動轉換。Automated migration between major database engine versions is currently not supported. 如果您希望升級至下個主要版本,請將資料庫備份和還原至使用新引擎版本所建立的伺服器。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.

還原時間點Point-in-time-restore

  • 使用 PITR 功能時,所建立新伺服器的設定會與作為新伺服器基礎的伺服器設定相同。When using the PITR feature, the new server is created with the same configurations as the server it is based on.
  • 不支援還原已刪除的伺服器。Restoring a deleted server is not supported.

VNet 服務端點VNet service endpoints

  • VNet 服務端點的支援僅適用於一般用途伺服器和記憶體最佳化伺服器。Support for VNet service endpoints is only for General Purpose and Memory Optimized servers.

儲存體大小Storage size

  • 如需每個定價層的儲存體大小限制,請參閱定價層Please refer to pricing tiers for the storage size limits per pricing tier.

目前已知問題Current known issues

  • MySQL 伺服器執行個體於建立連線後會顯示錯誤的伺服器版本。MySQL server instance displays the wrong server version after connection is established. 若要取得正確的伺服器執行個體引擎版本,請使用 select version(); 命令。To get the correct server instance engine version, use the select version(); command.

後續步驟Next steps