topic Re: ODBC with CDC backend is progressDBwith update expression. in Qlik Replicate

ODBC with CDC backend is progressDBwith update expression.

Snigdha174 — Thu, 09 May 2024 20:33:21 GMT

We are trying to do CDC process in qlik with ODBC connection and backend is ProgressDB.

For CDC we found in source connections, under Change processing we have Context Column settings and Expressions to identify Update and Delete Operations.

What is the definition of context column, what if we have all the column at source apart from primary key any non-primary key changes how will qlik identify the changes. Is it possible or do we have to ive update expression.

and if we have to provide update expression please let provide us an example how the update expression.

Thanks,

snigdha

Re: ODBC with CDC backend is progressDBwith update expression.

Heinvandenheuvel — Thu, 09 May 2024 21:32:20 GMT

Replicate will know nothing about your data, no before/after image, nothing.

Therefor it has to rely on something you tell it to first identify a row of interest it has not processed before and second why it is interesting. Ideally the first marker is an 'event-id' which always increases. Easiest is perhaps a high granularity 'insert' or 'last-update' date column. For inserts only, a PK or ID column, which every increasing unique value can do the job.

For update/delete it pretty much has to be a last-update date-time or such artificial event-id because the ID/PK does not change typically does not change on an update.

The update expression could then perhaps be a non-blank 'last-update-username', Or indeed a flag column it an 'UPDATE' or 'U' piece of string in it.

For delete it could be one or more blank columns which normally have a value. For example an insert-date being cleared pretty much has to mean the record can be deleted. Or that flag-column with a DELETE or 'D' marker in it.

Pretty? No?

Will it be workable for some source feeds? Yes.

Will it be workable of any source feed? No.

Good luck! You'll need it.

Hein.

Re: ODBC with CDC backend is progressDBwith update expression.

SushilKumar — Tue, 14 May 2024 04:04:32 GMT

Hello @Snigdha174

Seems progressDB is not yet certified with QR for Data Replication. However, There are some DB which can be configured with ODBC which require professional service engagement .

below link may provide some help full info.

https://help.qlik.com/en-US/replicate/November2023/Content/Replicate/Main/Support%20Matrix/supported_platforms.htm

https://help.qlik.com/en-US/replicate/November2023/Content/Replicate/Main/ODBC%20with%20CDC/odbc_source_with_CDC.htm

Reagrds,

Sushil Kumar