topic Re: Duplicate Inserts occurring in the __ct table when I expect only Updates for it in Qlik Replicate

Duplicate Inserts occurring in the __ct table when I expect only Updates for it

harikesh_1991 — Fri, 30 Jan 2026 10:08:52 GMT

Hello All,

I recently created a qlik task with only store changes option and also having the updates set to "After image only".
Also FYI, the task is running in batch processing mode.
Now my concern is that , I see that there are 66,050 rows being inserted and 1697 rows being updated from the Monitor-> Change Processing Tab.
We are developing an informatica job which will pick up the data from the __ct table and then insert it into the actual table in the target (WIP_TRANSACTION_ACCOUNTS) which has a unique index defined(WIP_SUB_LEDGER_ID).
When I checked the __ct table, I see that there are null's present in the column WIP_SUB_LEDGER_ID, these are all Inserts and there are 1697 rows exactly. And when I checked the updates , there are 1697 rows as well. So it looks like for every update, there is also an insert occurring. However, this was not what I had expected.
Since I selected the 'After image only' , I expected there would be rows post update at the source.
Could you please advise? @john_wang @Dana_Baldwin

Regards,

Harikesh OP

Re: Duplicate Inserts occurring in the __ct table when I expect only Updates for it

DesmondWOO — Fri, 30 Jan 2026 10:33:37 GMT

Hi @harikesh_1991 ,

It appears that you’re using Oracle E‑Business Suite, so I’m assuming the source database is Oracle. Since you’re seeing null values in the WIP_SUB_LEDGER_ID column, please verify that supplemental logging is enabled for all columns involved.

Regarding the behavior where each update is accompanied by an insert, you can review the operations recorded in the _ct table. In Oracle EBS, I guess that certain processes may perform a two‑step operation—first inserting a placeholder or framework record, and then updating it with the actual values. This can result in both an insert and an update being captured.

Regards,
Desmond

Re: Duplicate Inserts occurring in the __ct table when I expect only Updates for it

harikesh_1991 — Tue, 03 Feb 2026 12:45:13 GMT

Thank you @DesmondWOO for your insights on this.
Its good to know that this is application driven rather than a qlik issue. However I have a query, I see that there is an update row which is set as "U" present in the __ct table today. So when I checked the source table, I see the creation date for this record is today and the last update date is also reflecting as today.
If the creation date at the source is today, aren't we supposed to get it as "Insert" and not "Update" ?

Could you please advise on this?
I have attached the screenshot of the example.
Please let me know if you need diagnostic package or logs etc for checking.

Re: Duplicate Inserts occurring in the __ct table when I expect only Updates for it

harikesh_1991 — Wed, 04 Feb 2026 06:07:48 GMT

Hello @Dana_Baldwin @john_wang @DesmondWOO

Could anyone help to understand how the inserts,updates and deletes work in "store changes only" task for which the update is : "After Image only".
For example: I see a row with creation date as 03/02/2026 at source, however in the __ct table, it reflects as an update for the same date (03/02/2026) and not an insert.
Also the supplemental logging is active for all the columns at the source.

Regards,
Harikesh OP

Re: Duplicate Inserts occurring in the __ct table when I expect only Updates for it

john_wang — Wed, 04 Feb 2026 11:07:46 GMT

Hello @harikesh_1991 ,

Thanks for the update.

We recommend opening a support ticket and providing the following information:

If the issue is not related to the table structure, please try reproducing the behavior using a simple test table, for example:

create table kit(id integer not null primary key, name char(20));
Provide the table supplemental logging settings
Set both source_capture/target_apply to Verbose
Run the task and reproduce the issue
Download the Task Diagnostics Package and attach it to the support ticket
Please remember to decrypt the verbose task log file and attach it as well

Once we receive the above, we’ll be happy to investigate the issue further.

Good luck,

CC @Dana_Baldwin @DesmondWOO

John.