Oracle Goldengate Faq's

Oracle Goldengate Faq's

Question: What is a checkpoint table?

Answer: A checkpoint table is a small table in the target database used by the Replicat process to maintain checkpoints. A checkpoint records a known position in the trail from which to start after an expected or unexpected shutdown. By default, a record of these checkpoints is maintained in a file on disk in the GoldenGate directory. Optionally, the checkpoint record can also be maintained in a checkpoint table in the target database.

Question: Why should I use a checkpoint table?

Answer: Using a checkpoint table (database checkpointing) is recommended because it enables the checkpoint to be included within Replicat's transaction, which improves recovery in certain situations. If you elect not to use a checkpoint table, data integrity will still be maintained by means of the checkpoint file on disk, although there may be correctable database errors in those circumstances that otherwise would be handled by means of database checkpointing.

Question: How large will the checkpoint table get?

Answer: The checkpoint table should remain small because rows are deleted when no longer needed, and it will not affect database performance.

Question: Does it matter where I create this table?

Answer: The checkpoint table can reside in a schema of your choice, but GoldenGate recommends using one that is dedicated to GoldenGate.

Question: Do I need a checkpoint table for each Replicat or each instance of GoldenGate on a system?

Answer: No. You only need to create one checkpoint table for all GoldenGate installations and Replicat groups. GoldenGate keeps track of the checkpoints, even if Replicat group names are the same in different instances.

Question: Could I use different checkpoint tables for different groups if I want?

Answer: Yes. Use as many as you like to customize database checkpointing to your needs. If you like, you can specify a default checkpoint table (recommended) and also specify overrides to the default as needed. When you use a default checkpoint table, you do not have to remember its name or specify it whenever you add new Replicat groups.