transaction_isolation

Description

transaction_isolation specifies the transaction isolation level. It has the same functionality as the system variable tx_isolation. You can set either variable.

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 obtain the value of a global system variable.

  • 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 obtain the value of a session system variable.

• Modify variables

  • Global level

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

Attributes

Examples

Set the transaction isolation level to READ-COMMITTED.

• Session level

  obclient> SET transaction_isolation = 'READ-COMMITTED';
  

• Global level

  obclient> SET GLOBAL transaction_isolation = 'READ-COMMITTED';
  

References

For more information about transaction isolation levels, see Overview of transaction isolation levels.