This topic describes the limits of the EMR Serverless StarRocks service.
Billing methods: Both subscription and pay-as-you-go billing methods are supported.
Follow these naming conventions for instance, database, table, view, column, partition, username, and role names:
A name can contain only digits (0-9), letters (a-z or A-Z), and underscores (_). A username can consist of only digits.
A name cannot exceed 64 characters. A column name cannot exceed 1,023 characters.
Database, table, view, partition, and role names must start with a letter. A column name can start with a letter or an underscore (_).
Database names, table names, and view names are case-sensitive. Column names are case-insensitive.
Column names cannot be modified.
Label names: When you import data, you can specify a label for the task. A label name can be up to 128 characters long. It can contain only digits (0-9), letters (a-z or A-Z), and underscores (_). It must start with a letter, a digit, or an underscore.
Table creation constraints:
Key columns cannot be of the FLOAT or DOUBLE type. Use the DECIMAL type to represent decimal values.
The length of a VARCHAR value ranges from 1 to 1,048,576 bytes. This is calculated as follows: 1,048,578 (maximum row size) - 2 (length identifier) = 1,048,576.
Encoding: StarRocks supports only UTF-8 encoding. Other encoding methods, such as GB, are not supported.
Subquery limit: By default, the maximum number of subqueries in a query is 10,000.
When you design a table, you must adhere to the core parameter configurations listed below. If you change these parameters from their default values, the product guarantee for the instance is voided. This can cause critical failures or data threats.
Parameter value
Parameter name
Default value
Applicable version
Impact description
replication_num
Number of replicas
3
Coupled compute and storage
If you change the number of replicas to 1 or 2, you risk data loss. This can also cause issues such as computing skew, which can lead to node breakdowns.
enable_persistent_index
Enable primary key index persistence
true
All versions
If you set this to false, the primary key index is not persisted to disk. Instead, it is temporarily stored in memory. This can lead to a series of issues, such as data loss, data duplication, and node breakdowns.
persistent_index_type
Persistence index type
CLOUD_NATIVE
Decoupled compute and storage
If you set this to LOCAL, you may lose control of disk space, which makes the instance unusable.