System limits

This topic describes the rules and limits that apply when you use StarRocks.

  • StarRocks uses the MySQL protocol for communication. You can connect to the StarRocks cluster via a MySQL client or JDBC. We recommend that you use a MySQL client whose version is 5.1 or later. Versions earlier than 5.1 do not support usernames that are longer than 16 characters.

  • Naming conventions for clusters, databases, tables, views, columns, partitions, usernames, and roles:

    • The names can only consist of digits (0-9), letters (a-z or A-Z), and underscores (_).
    • The name cannot exceed 64 characters in length.
    • Except for column names, other names must start with a lowercase or uppercase letter.
    • Column names can start with an underscore (_).
    • Database, table, and view names are case-sensitive. Column names are not case-sensitive.
  • Naming conventions for labels: You can specify the label of a job when you import data. The label name can consist of underscores (_), letters (a-z or A-Z), and digits (0-9), and cannot exceed 128 characters in length. The label name has no requirement for the starting character.

  • When you create a table, the key column cannot be of the FLOAT or DOUBLE type. You can use the DECIMAL type to represent decimals.

  • A VARCHAR value can be up to 65533 bytes (two bytes less than 65535 because the first two bytes are used to indicate the length).

  • StarRocks supports only UTF8 encoding, not GBK.

  • StarRocks does not support modifying column names in tables.

  • By default, an expression can have a maximum of 10,000 children, which can be modified by using expr_child_limit in the fe.conf file.

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