At a minimum, each customized operator must define the user-provided control functions listed in the following table.
Function | Use |
---|---|
Initiate | Preparing the operating environment for executing operators by performing the following tasks:
|
Execute | Performing the following data access and manipulation tasks:
|
Checkpoint | Writing checkpoint records to a restart log table that the operator can use to restart in case of a hardware or software system failure. |
Restart | Restarting operators using the most recently written checkpoint records. |
Event | Performing event processing or notification based on caller-specified event. |
Terminate | Releasing system resources allocated by the corresponding Initiate function. |