Constraints

Storage space

• Pay-per-use instance: a maximum of 128,000 GB
• Yearly/monthly instance: 40 GB to 128,000 GB
• Serverless instance: a maximum of 128,000 GB
• Standard HTAP instance: 50 GB to 32,000 GB for backend nodes; 50 GB to 1,000 GB for frontend nodes

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Temporary disk space

500 GB at most

For more information, see How Can I Use Temporary Disk of GaussDB(for MySQL)?

Connections

GaussDB(for MySQL) does not have constraints on the number of connections. This number is determined by the default value and value range of the DB engine.

For more information, see What Is the Maximum Number of Connections to a GaussDB(for MySQL) Instance?

GaussDB(for MySQL) instances

50 instances at most

For details about how to increase the quota, see Increasing Quotas.

Read replicas

• A single yearly/monthly instance: 0 to 15 read replicas
• A single pay-per-use instance: 0 to 15 read replicas
• A single serverless instance: 0 to 7 read replicas

For more information, see Introducing Read Replicas.

Tags

A maximum of 20 tags for each instance

For more information, see Managing Tags.

Free backup space

About 100% of the purchased storage space

For more information, see How Is GaussDB(for MySQL) Backup Data Billed?

Automated backup retention period

• Same-region backup: 7 days by default. The value ranges from 1 to 732 days. You can contact customer service to extend the retention period to 3,660 days.
• Cross-region backup: 1 to 1,825 days

For more information, see Configuring a Same-Region Backup Policy and Configuring a Cross-Region Backup Policy.

Log retention period

• Error log details: 30 days
• Slow query log details: 30 days
• Slow query logs with Show Original Log enabled: 30 days

For more information, see Log Management.

Instance name

The name must start with a letter and consist of 4 to 64 characters. Only letters, digits, hyphens (-), and underscores (_) are allowed.

For more information, see Changing a DB Instance Name.

Database name

• The database name must consist of 1 to 64 characters. Only letters, digits, hyphens (-), and underscores (_) are allowed. The total number of hyphens (-) cannot exceed 10.
• To prevent errors, reserved keywords cannot be used.

For more information, see Creating a Database.

Username

• The username must consist of 1 to 32 characters. Only letters, digits, and underscores (_) are allowed.
• To prevent errors, reserved keywords cannot be used.

For more information, see Creating a Database Account.

Parameter template name

The template name must consist of 1 to 64 characters. Only letters (case-sensitive), digits, hyphens (-), underscores (_), and periods (.) are allowed.

For more information, see Creating a Parameter Template.

Backup name

The name must start with a letter and consist of 4 to 64 characters. Only letters, digits, hyphens (-), and underscores (_) are allowed.

For more information, see Creating a Manual Backup.

Table name/function name/stored procedure name/view name

To prevent errors, reserved keywords cannot be used.

For more information, see Database Table Usage.

Database root permissions

Only the root user permissions are available on the instance creation page.

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Account password

• It must consist of 8 to 32 characters.
• It must contain at least three types of the following characters: uppercase letters, lowercase letters, digits, and the following special characters: ~!@#$%^*-_=+?,()&|.
• It cannot be the username or the username spelled backwards.
• It must comply with the values of validate_password parameters.

  To check the password-related parameter values, click an instance name, choose Parameters in the navigation pane, and search for validate_password in the upper right corner of the page.

For more information, see Resetting the Administrator Password.

Port

• The default value is 3306 and can be changed manually.
• The database port ranges from 1025 to 65534, excluding 5342, 5343, 5344, 5345, 12017, 20000, 20201, 20202, 33062, 33060, and 33071, which are reserved by the system.

For more information, see Changing a Database Port.

VPC

After a GaussDB(for MySQL) instance is created, the VPC cannot be changed.

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Security group

• By default, you can create a maximum of 100 security groups in your cloud account.
• By default, you can add a maximum of 50 rules to a security group.
• One GaussDB(for MySQL) instance can be bound to multiple security groups, and one security group can be associated with multiple GaussDB(for MySQL) instances.
• When creating an instance, you can select multiple security groups. (For better network performance, you are advised to select no more than five security groups.)

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System accounts

To provide O&M services, the system automatically creates system accounts when you create instances. These system accounts are unavailable to you.

• rdsAdmin: a management account with highest permissions, which is used to query and modify instance information, rectify faults, migrate data, and restore data.
• rdsRepl: a replication account, which is used to synchronize data from primary DB instances to standby DB instances or read replicas.
• rdsBackup: a backup account, which is used to back up data in the background.
• rdsMetric: a metric monitoring account, which is used by watchdog to collect database status data.
• rdsProxy: a database proxy account, which is used for authentication when the database is connected through the proxy address. This account is automatically created when you enable read/write splitting.

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Instance parameters

Most parameters can be modified through the console or APIs. To ensure security and stability of instances, some parameters cannot be modified.

For more information, see Modifying Parameters of a GaussDB(for MySQL) DB Instance.

MySQL storage engine

GaussDB(for MySQL) supports only the InnoDB storage engine.

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GaussDB(for MySQL) access

• If GaussDB(for MySQL) instances do not have EIPs bound, the instances must be in the same VPC subnet as the ECSs associated with these instances.
• Security group rules must be added to allow ECSs to access GaussDB(for MySQL) instances.

  By default, a GaussDB(for MySQL) instance cannot be accessed by an ECS in a different security group. To enable access, you must add an inbound rule to the security group of a GaussDB(for MySQL) instance. When adding the rule, set the protocol and port, respectively, to TCP and to the default database port of the instance.

• Port of a GaussDB(for MySQL) instance:

  The default port is 3306. You can change it if you want to access GaussDB(for MySQL) through another port over a private or public network.

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Data migration

DRS or mysqldump can be used to migrate data to GaussDB(for MySQL).

For more information, see Data Migration.

GaussDB(for MySQL) instance reboot

Instances can only be rebooted on the GaussDB(for MySQL) console.

For more information, see Rebooting a DB Instance.

GaussDB(for MySQL) backups

GaussDB(for MySQL) backups are stored in OBS buckets and are not visible to you.

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Binlog function

Binlog cannot be enabled for GaussDB(for MySQL) read replicas.

For more information, see How Do I Enable and View Binlog of My GaussDB(for MySQL) Instance?

Partitioned tables

GaussDB(for MySQL) is compatible with MySQL Community Server 8.0.22. For a list-partitioned table, there are up to 256 values in a partition, or an error is reported. (Workaround: Redistribute the contents of one table partition into multiple partitions.)

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Small-scale instances

For GaussDB(for MySQL) instances with 2 vCPUs and 8 GB memory, the total number of tables in a single instance cannot exceed 300,000, and the number of tables in a single database cannot exceed 5,000.

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