To ensure the stability and security of clusters, AnalyticDB for MySQL is subject to the limits described in the following tables.

Object Naming convention Limits
Database A database name can be up to 64 characters in length and can contain letters, digits, and underscores (_). It must start with a lowercase letter and cannot contain consecutive underscores (_). Do not use analyticdb as the database name. The name analyticdb is reserved for built-in databases.
Table A table name must be 1 to 127 characters in length and can contain letters, digits, and underscores (_). It must start with a letter or underscore (_).
  • A table name cannot contain single quotation marks ('), double quotation marks (''), exclamation points (!), or spaces.
  • A table name cannot be an SQL reserved word.
Column A column name must be 1 to 127 characters in length and can contain letters, digits, and underscores (_). It must start with a letter or underscore (_).
  • A column name cannot contain single quotation marks ('), double quotation marks (''), exclamation points (!), or spaces.
  • A column name cannot be an SQL reserved word.
Account An account name must be 2 to 16 characters in length and can contain lowercase letters, digits, and underscores (_). It must start with a lowercase letter and end with a lowercase letter or digit. None
Password A password must be 8 to 32 characters in length and contain at least three of the following character types: uppercase letters, lowercase letters, digits, and special characters. Special characters include ! @ # $ % ^ & * ( ) _ + - = None
Table comment None A table comment can be up to 1,024 characters in length.
Column comment None A column comment can be up to 1,024 characters in length.
Index None An index name can be up to 64 characters in length.
Default value of a column None The default value of a column can be up to 127 characters in length.
Data None Data is case-sensitive.
Collation None Only utf8_general_cs is supported. It cannot be modified.

Limits on purchase and configurations

Limits Description
Maximum number of clusters that can be purchased within each Alibaba Cloud account 64
Maximum number of node groups that can be purchased for each cluster in reserved mode for Cluster Edition 128
Range of disk space that can be purchased for each cluster in reserved mode for Cluster Edition
  • C8: 100 GB to 2,000 GB
  • C32: 100 GB to 8,000 GB
Maximum number of databases that can be created in each cluster 256
Total number of scale-in, scale-out, upgrade, and downgrade operations on each cluster per day 12
Maximum disk space usage for node groups of a cluster in reserved mode for Cluster Edition 90%
Note If the disk space usage of a cluster exceeds this limit, the cluster is locked and data cannot be written to the cluster.
Maximum amount of hot data per node for a cluster in elastic mode 4 TB
Note If the amount of hot data per node exceeds 4 TB, the cluster is locked and cannot have data written.
Maximum number of standard accounts that can be created for each cluster 256
Maximum number of connections that can be established to each cluster 5,000
Maximum number of tables that can be created in each cluster
  • Reserved mode

    Cluster Edition: If a cluster contains 1 to 20 node groups, a maximum of 5,000 tables can be created in the cluster. You can increase the number of tables by increasing the number of nodes.

  • Elastic mode

    If the computing resources of a cluster contain 1,440 or fewer cores, a maximum of 5,000 tables can be created in the cluster. You can increase the number of tables by increasing the number of nodes.

Maximum number of columns in each table 4,096
Maximum number of partitions in each cluster 102,400
Maximum number of IP addresses that can be added to whitelists in each cluster 25,000
Note Each cluster can have up to 50 whitelists created. Each whitelist can contain up to 1,000 IP addresses.
Maximum number of items that can be specified in the WHERE clause 256
Maximum number of conditions that can be specified by using the IN operator 2,000
Maximum length of data that can be written to each row 16 MB
Maximum length of each field 16 MB
Valid values of the M and D parameters in the DECIMAL(M,D) data type M is the maximum precision, and it ranges from 1 to 1000. D is the decimal scale. The value of D must be less than or equal to that of M.

Limits on operations

Operation Timeout period (unit: ms) Description
Create a cluster 600,000 None
Delete a cluster 300,000 None
Scale up a cluster 600,000 None
Create a database 10,000 None
Delete a database 10,000 None
Create a table or view 10,000 None
Delete a table or view 10,000 None
Add a column 10,000 None
Remove a column 60,000 None
Update a column 60,000 None
TRUNCATE TABLE 60,000 None
Query data 1,800,000 When a query times out, the system ends the query. You can modify the maximum execution duration of a query by using the following parameter and hint:
  • Parameter: QUERY_TIMEOUT
  • Hint: query_timeout
Note The system checks timeout queries every 1,000 ms. Therefore, the maximum execution duration of a query must be set to a value greater than 1,000 ms. Otherwise, the query_timeout hint may not take effect.
Write data 300,000 None
INSERT + SELECT FROM/UPDATE FROM/DELETE FROM 24 × 3,600,000 When a task times out and ends, you can modify the maximum execution duration of the INSERT + SELECT FROM/UPDATE FROM/DELETE FROM statement by using the following parameter and hint:
  • Parameter: INSERT_SELECT_TIMEOUT
  • Hint: insert_select_timeout