The API package usually contains multiple procedures to insert, update, or delete application data; the API procedures are executed when they are called by other PL/SQL modules, by a direct SQL*Plus call, or through a front end such as the Data Pump. The APIs do not issue commits. When a user-defined procedure or script calls the API procedure, the calling module must manage transaction commit statements. The calling module should also address exception handling and logging to delivered exception tables. The API package should never be modified. Oracle cannot support modified APIs nor systems that have used modified APIs, because HRMS data integrity could be compromised. APIs can be used as building blocks called within an extensive customer-defined package. Unique functionality can be addressed with API User Hooks or other user code, providing that Oracle HRMS data is modified only through the call to the delivered API.