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

Object Naming convention Limit
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 a built-in database.
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 must contain at least three of the following character types: uppercase letters, lowercase letters, digits, and special characters. Special characters include ! @ # $ % ^ & * ( ) _ + - = None
Comment in a table None A table comment can be up to 1,024 characters in length.
Comment in a column None A column comment can be up to 1,024 characters in length.
Index name 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.

Limits on purchase and configurations

Limit Description
The maximum number of clusters that can be purchased within each Alibaba Cloud account 64
The maximum number of node groups that can be purchased for each cluster 200
The range of disk space that can be purchased for each cluster 100 GB to 200 GB
The minimum number of nodes that can be purchased for each cluster 2
The maximum number of databases that can be created in each cluster 256
The total number of scale-in, scale-out, upgrade, and downgrade operations on each cluster per day 12
The threshold of the disk space usage for node groups 90%
Note If the disk space usage of a cluster exceeds this threshold, the cluster is locked, and data cannot be written to the cluster.
The maximum number of standard accounts that can be created for each cluster 256
The maximum number of connections that can be established with each cluster 5,000
The 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 scaling out the number of nodes.

  • Elastic mode

    If computing resources of a cluster contain up to 1,440 cores, a maximum of 5,000 tables can be created in the cluster. You can increase the number of tables by scaling out the number of nodes.

The maximum number of columns in each table 4,096
The maximum number of partitions in each cluster 102,400
The maximum number of IP addresses that can be added to whitelists in each cluster 25,000
Note You can create up to 50 whitelists within each cluster and add up to 1,000 IP addresses to each whitelist.
The maximum number of items that can be specified in the WHERE clause 256
The maximum number of conditions that can be specified by using the IN operator 2,000
The maximum length of data that can be written in each row 16 MB
The maximum length of each field 16 MB
The valid values of the M and D parameters in the DECIMAL(M,D) data type M is the maximum precision, and its value range is 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) Timeout description
Create a cluster 600,000 None
Delete a cluster 300,000 None
Scale out 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
Insert a column 10,000 None
Delete 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 modifying the following configurations:
  • Parameter: queryTimeout
  • Hint: query_timeout
Note The system detects 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 24 × 3,600,000 When a task times out and ends, you can modify the maximum execution duration of the INSERT SELECT FROM statement by modifying the following configurations:
  • Parameter: insertSelectTimeout
  • Hint: insert_select_timeout
INSERT OVERWRITE 24 × 3,600,000 When a task times out and ends, you can modify the maximum execution duration of the INSERT OVERWRITE statement by modifying the following configurations:
  • Parameter: insertSelectTimeout
  • Hint: insert_select_timeout