tx_isolation

Description

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

Privilege requirements

• Query variables

  • Global level

    You 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 get the value of a global system variable. This operation is supported for the sys tenant and all user tenants of the MySQL mode and Oracle mode.

  • Session level

    You 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 get the value of a session system variable. This operation is supported for the sys tenant and all user tenants of the MySQL mode and Oracle mode.

• Modify variables

  • Global level

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

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

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

  • Session level

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

Attributes

Examples

Set the transaction isolation level to READ-COMMITTED.

• Session level

  obclient> SET tx_isolation = 'READ-COMMITTED';
  

• Global level

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

References

For more information about transaction isolation levels, see Overview.