When to Implement User Exits

You can employ user exits as an alternative to, or in conjunction with, the column-conversion functions that are available within Oracle GoldenGate. User exits can be a better alternative to the built-in functions because a user exit processes data only once (when the data is extracted) rather than twice (once when the data is extracted and once to perform the transformation).

The following are some ways in which you can implement user exits:

• Perform arithmetic operations, date conversions, or table lookups while mapping from one table to another.

• Implement record archival functions offline.

• Respond to unusual database events in custom ways, for example by sending an e-mail message or a page based on an output value.

• Accumulate totals and gather statistics.

• Manipulate a record.

• Repair invalid data.

• Calculate the net difference in a record before and after an update.

• Accept or reject records for extraction or replication based on complex criteria.

• Normalize a database during conversion.