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

Object Naming convention Limit
Database name A database name can be up to 64 characters in length, and can contain letters, digits, underscores (_), and hyphens (-). It must start with a lowercase letter and cannot contain consecutive underscores (_).
Note Enclose hyphens with backticks (``). Example: create database `adb--demo`;.
A database name cannot be analyticdb. This name is reserved for built-in databases.
Table name 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 quotation marks ('), exclamation marks (!), or spaces.
  • A table name cannot be SQL reserved keywords.
Column name 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 quotation marks ('), exclamation marks (!), or spaces.
  • A column name cannot be SQL reserved keywords.
Account name 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. N/A
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 ! @ # $ % ^ & * ( ) _ + - = N/A
Comment in a table N/A A table comment can be up to 1,024 characters in length.
Comment in a column N/A A column comment can be up to 1,024 characters in length.
Index name N/A An index name can be up to 64 characters in length.
Default value of a column N/A The default value of a column can be up to 127 characters in length.

Limits on purchase and configuration

Limit Description Remarks
The maximum number of clusters that you can purchase under each Alibaba cloud account 64 N/A
The minimum number of node groups that you can purchase for each cluster 2 N/A
The maximum number of databases that you can create in each cluster 256 N/A
The total number of scale-in, scale-out, upgrade, and downgrade operations on each cluster per day 12 N/A
The threshold of the disk space usage for node groups 80% If the disk space usage of a cluster exceeds this threshold, the cluster will be locked and data cannot be written to the cluster.
The maximum number of standard accounts that you can create for each cluster 256 N/A
The maximum number of connections that you can establish with each cluster 5,000 N/A
The maximum number of tables that you can create in each cluster
  • Two node groups: 800
  • Other node group types: min(256 × Number of node groups, 20000)
N/A
The maximum number of columns in each table 1,024 N/A
The maximum number of partitions in each table 102,400 N/A
The maximum number of IP addresses that you can add to whitelists in each cluster 25,000 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 you can specify in the WHERE clause 256 N/A
The maximum number of conditions that you can specify by using the IN operator 2,000 N/A
The maximum length of data that you can write in each row 16 MB N/A
The maximum length of each field 16 MB N/A
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. N/A

Limits on operations

Operation Timeout period (unit: ms) Timeout description
Create a cluster 600,000 N/A
Delete a cluster 300,000 N/A
Scale out a cluster 600,000 N/A
Create a database 10,000 N/A
Delete a database 10,000 N/A
Create a table or view 10,000 N/A
Delete a table or view 10,000 N/A
Insert a column 10,000 N/A
Delete a column from a table 60,000 N/A
Update a column 60,000 N/A
TRUNCATE TABLE 60,000 N/A
Query data 1,800,000 When a query times out, the system automatically ends the query. You can modify the maximum execution time of a query by modifying the following configuration:
  • Parameter: queryTimeout
  • Hint: query_timeout
Write data 300,000 N/A
INSERT SELECT FROM 24 × 3,600,000 When a task times out and ends, you can modify the maximum execution time of the INSERT SELECT FROM statement by modifying the following configuration:
  • 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 time of the INSERT OVERWRITE statement by modifying the following configuration:
  • Parameter: insertSelectTimeout
  • Hint: insert_select_timeout