Oracle Goldengate Extract process Use Cases

 You can Configure Oracle Goldengate Extract Process in the following 2 types of use cases.

1. Initial Load

• When you set up Oracle Goldengate Extract process for Initial Loads, the extract process captures the current, static set of data directly from the source objects.
• The configuration of the extract process uses source tables as the source to capture data.

2. Online Extract (Change Synchronization)

• When you set up Oracle Goldengate to keep the source data synchronized with another set of data, the extract process captures the DML and DDL operations performed on the configured objects after the initial synchronization has taken place.
• Extract can run locally (upstream) on the same server as the database or on another server using the Downstream Extract process.
• Extract process stores these operations until it receives commit records or rollbacks for the transactions that contain them.
• If it receives a rollback - it discards the operations for that transactions.
• If it receives a commit, it persists the to transactions to disk in a series of files called a trail, where it is queued for propagation to the target system.
• All the operations in each transaction are written to the trail as a sequentially organized transaction unit and are in the order in which they were committed to the database (Commit Sequence Order).
• This Configuration of the extract process uses database recovery logs or transaction logs as the data source.