0

We are planing to setup an Oracle 12c RAC with a Logical standby in the DR site.

Since data consistency is extremely important, we our planning to setup redo log shipping to be in SYNC mode.

Our application which also runs on the Secondary site (redundant processes) requires the DB to be in write mode, hence the Logical standby option was chosen. Application on the Primary site DB with write to one tablespace (Say A). And on the secondary site it will write to a separate tablespace (Say B).

Our client's application writes to a tablespace (Say C) and needs it to be in sync across both sites.

The main idea behind doing the above is to stop large number of redo logs bring shipped to the secondary site via the WAN. Our application already has the ability to sync the inputs to the system. And since one input generates several DB inputs (and redo logs), we thought of writing to the databases independently will be the better option.

My Question is, can we configure the primary site to send selective redo logs to the logical standby. From what I know, all redo logs are shipped on-the-fly to the secondary site in SYNC mode and we can configure the logical standby to omit sqls for tablespace A.

2

Not possible, redo logs get transferred unprocessed. If you want to transfer changes related to just some specific objects or schemas, Streams (deprecated, but free) or GoldenGate (requires extra license) does that.

Another option for reducing network traffic is to configure redo transport compression (requires the Advanced Compression option), but this could still produce much more network traffic compared to above solutions depending on the ratio of the changes related to the replicated objects.

| improve this answer | |
  • Thank you for your response. Can GoldenGate be configured to apply logs in sync mode to the standby DB. i.e commit on primary DB guarantees data is available on the standby DB ? Also is it possible to have the Standby DB in read/write mode so the application can write from the secondary site ? – Ahamed Fazlul Wahab Jul 3 '15 at 5:23

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.