parallel_degree_limit

Description

parallel_degree_limit specifies the upper limit of the parallel degree selected by the optimizer when the Auto DOP strategy is used.

Privilege requirements

• Query variables

  • Global level

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

  • Session level

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

• Modify variables

  • Global level

    • sys tenants can directly modify the values of global system variables.

    • MySQL user tenants must have the SUPER or ALTER SYSTEM privilege to modify the values of global system variables.

    • Oracle user tenants must have the ALTER SYSTEM privilege to modify the values of global system variables.

  • Session level

    sys tenants and all user tenants can directly modify the values of session system variables.

Attributes

Examples

Set the upper limit of the parallel degree selected by the optimizer 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;