Saving initial Snapshot and Final Snapshot

Hello dear Knimers!

Please can you give some hint in order to save initial data and final data.
My data changes incrementally weekly and monthly, and I have to get initial value and changed value as in this example

So at the end of my task is to get values before changes and after changes as well

I tried to do simple workflow, but it works for only one change. If there will be some other changes it does not work.
I created two readers, because I wanted to save not changed file as one reader and wanted to join with changed one. But in this case it will not work recursively
test.knwf (27.5 KB)

Hi @Karlygash , Knime is not meant as a data storage, so I don’t understand why you are trying to do this…

Yes, you can save your workflow with data, and you can fork you workflow to get data at different stages, but all of this is not meant for permanent storage. The moment any node is reset on the upstream, your data is gone, and if your source data changed, you won’t get the same data again even if you re-run the workflow.

For permanent data snapshot, you should save that data either in a file, or in a db table.

Can you explain what is the purpose behind this? If it’s to show the different results within the workflow, then that’s fine, but as I said, if source data is changed and workflow is reset, your “snapshot” will no longer be the same.

It all depends on what you’re trying to achieve.


Hello there,

@bruno29a don’t think this is about storage as data is being exported in workflow.

@Karlygash I don’t understand what do you mean that workflow won’t work recursively? What is your goal? To add new column each time data changes? You might end up with many columns… Usually what I have seen people do to trach changes is to add new row if data changes and leave it as is if not.

Anyways if you share 3 (dummy) example files and desired output with logic explained if not obvious I’m sure we’ll come up with something useful :wink:


Hello, @ipazin , @bruno29a
Thanks for your response :innocent:
Unfortunately I have just sample
The purpose is to save and get initial snapshot and final snapshot after changes.
I have just this single scenario

Lets say user changes 5th Row 20 to 40. At the end I have to save initial and final snapshot as well

Hello @Karlygash,

maybe one Cell Replacer will do it? Take a look at attached example.
2021_08_18_Snapshots.knwf (13.0 KB)


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