topic The beforeData values are not the previous data values. Why? in Qlik Replicate

The beforeData values are not the previous data values. Why?

jvagg_qlik — Fri, 29 Apr 2022 00:01:40 GMT

I am using replicate and using a source of aurora Postgres and target of Kafka topic. For all update messages I see the data section and beforeData section. All documentation shows the beforeData should be all the previous data values before the update. In my case this is not true. I see tue same values except for the PK. The before data is null and new data has a value. All other fields are the same values. This is true for any update even if the other data elements are changing. The PK is not being changed at all.

Does anyone know why this is happening?

Re: The beforeData values are not the previous data values. Why?

Michael_Litz — Fri, 29 Apr 2022 00:22:15 GMT

Hi,

I just checked the user guide for Aurora Postgres source and one of the limitations is that Before Image is not supported, that is why you are seeing Nulls.

Thanks
Michael

Re: The beforeData values are not the previous data values. Why?

jvagg_qlik — Fri, 29 Apr 2022 11:56:20 GMT

Ok thank you. I was not sure if that limitations referred to this ability. Since I am trying to see what changed and send that info to Kafka, are there any work arounds that may work? If I select only the columns I want from the source table vs all the columns, will the UPDATE message only come into Kafka if any of those columns changed? Or will will send the UPDATE message if any column changed, even if I did not select it in the replicate task?

Looking for any recommendations to achieve this.

Thanks

Jeff

Re: The beforeData values are not the previous data values. Why?

lyka — Fri, 29 Apr 2022 22:32:10 GMT

Hi Jeff,

Only the columns that are included in Replicate and that were changed will be included.

Thanks

Lyka