DataStage and CDC

ferreirahe · Post by **ferreirahe** » Tue Jul 19, 2005 4:58 pm

Hi all,

I have posted a topic here just minutes ago regarding SAP IS-U. That same customer also wants to know about data change detection in data sources.

I gather this is a matter for CDC. They have Oracle.

I have not found any white papers for CDC.

I assume they must have in place a replication server or a similar mechanism to log all changes to the database. Is the CDC going to detect the changes to the data? How does it do it?

Thanks for help.

Cheers,
Henrique Ferreira

vmcburney · Post by **vmcburney** » Tue Jul 19, 2005 6:15 pm

The Oracle change data capture component from Ascential does log scraping against the Oracle database engine to grab changes. You can also do change data capture within jobs using the CRC32 function. There is a download demo available from Ascential devnet.

We have two layers of CDC. We take delta data from a replica database using a timestamp. Once we take out the columns we don't need and do various data enrichment we then do changed data determination against the target table to see if the delta row is still different to those previously loaded.