Internal parameter for oracle physical standby setup to avoid FL + CDC issues.

[Shai_E]

Please note: This mini article serves as an addition to an already written section within the Replicate
User Guide.

When the Oracle LOG_ARCHIVE_DEST_n initialization parameter is configured with the DELAY option,
running a Full Load and Apply Changes task on an Oracle Physical Standby instance may result in missing or erroneous data in the target database.

Related read in the User Guide:

Supported Standby configurations ‒ Qlik Replicate (See Physical Standby, second bullet point)

Resolution:

Set the internal parameter:

'standbyDelayTime' (represented as minutes) >  than source database delay parameter.

[kutay_cilingiroglu]

Thanks for the article, it is very useful.

Suppose that "Delay" parameter is configured as 5-minute in standby database. Could you please suggest best/optimal "standbyDelayTime" parameter value for these configuration, 6-10 or more?

How can we prevent missing or erroneous data scenarios?

Many Thanks.

[KellyHobson]

Hey @kutay_cilingiroglu ,

Example:
standbyDelayTime: 6 > source database delay parameter: 5 min

Range of 6-10 minutes is sufficient. As long as standbyDelayTime is higher than the value set in LOG_ARCHIVE_DEST_n initialization parameter, than it will avoid missing data.

Note- It may lead a few redundant records for tables without PK/UI if there were INSERT operations during that period.

Please let us know if you have any additional questions.

Best,

Kelly