parallel_degree_limit

Description

parallel_degree_limit specifies the maximum parallel degree that the optimizer can choose when the Auto DOP strategy is used.

Privilege requirements

• Query variables

  • Global level

    sys tenant and all user tenants can execute the SHOW VARIABLES statement or query the SYS.TENANT_VIRTUAL_GLOBAL_VARIABLE (Oracle mode) or information_schema.GLOBAL_VARIABLES (MySQL mode) view to obtain the value of a global system variable.

  • Session level

    sys tenant and all user tenants can execute the SHOW VARIABLES statement or query the SYS.TENANT_VIRTUAL_SESSION_VARIABLE (Oracle mode) or information_schema.SESSION_VARIABLES (MySQL mode) view to obtain the value of a session system variable.

• Modify variables

  • Global level

    • sys tenant can directly modify the value of a global system variable.

    • MySQL user tenants must have the SUPER or ALTER SYSTEM privilege to modify the value of a global system variable.

    • Oracle user tenants must have the ALTER SYSTEM privilege to modify the value of a global system variable.

  • Session level

    sys tenant and all user tenants can directly modify the value of a session system variable.

Attributes

Examples

Set the maximum parallel degree that the optimizer can choose when the Auto DOP strategy is used to 256.

• Global level

  obclient> SET GLOBAL parallel_degree_limit=256;
  

• Session level

  obclient> SET parallel_degree_limit=256;