Limits - Quick Start for MySQL| Alibaba Cloud Documentation Center

To guarantee the stability and security of ApsaraDB for MySQL, certain limits to database and management properties apply.

Items	Restrictions
Parameter modification	The RDS console or API must be used to modify database parameters. But some parameters cannot be modified. For more information, see Setting parameters.
Root permission	The root or sa permission is not provided.
Restoration and backup	The command line or graphical interface can be used to perform logical backup. For physical backup, the RDS console or API must be used.
Migration	The command line or graphical interface can be used to perform logical import. You can use mysql command line tool or Data Transmission Service (DTS) to perform data migration.
Replication	MySQL provides a dual-node cluster of master/slave MySQL replications architecture, so you do not need to build them manually. The slave instance in the architecture is invisible to you, and your application cannot access to the slave instance directly.
MySQL storage engine	Currently only InnoDB and TokuDB are supported. The InnoDB storage engine is recommended for performance and security requirements. The Memory engine is not supported. Due to the defects inherent to the MyISAM engine, data may be lost. Therefore, any new instances generated with MyISAM engine are automatically converted to InnoDB table.
Restarting the RDS instance	Instance must be restarted through the RDS console or API.
User, password, and database management	By default, MySQL uses the RDS console to perform user, password, and database management such as creating or deleting an instance, modifying privileges and changing password. MySQL also supports creating a master account for finer-grained management controls.
Ordinary account	Does not support custom authorization. The account management and database management interfaces exist on the RDS console. The instance with ordinary accounts can create a master account. MySQL 5.7 Basic Edition instances do not support ordinary account.
Master account	Support custom authorization. The account management and database management interfaces disappear from the RDS console. To manage accounts and databases, use SQL statements. The account cannot be rolled back to the ordinary account. MySQL 5.7 Basic Edition instances only support master account.
Network setting	If a MySQL 5.5/5.6 instance is in a classic network and its access mode is safe connection mode, do not enable net.ipv4.tcp_timestamps in SNAT mode.