Aggregrating Data

I am trying to aggregate data in KNIME and trying to use the Group By node. However, I can’t get the node to work.

Can someone explain what is the best way to use the node? I have over 20 columns and want to group the data by year. What is the difference between the Groups and Manual Aggregation options?

Here is a screenshot.

  1. What exactly do you mean when you say you can’t get the node to work?
  2. Have you read the node description?
  3. You say you want to group the data by year. But what does that actually mean? What happens after the grouping? What data do you want preserved? Do you have an example of your desired output?

Hi @ssen
Group is for the key column which should be kept and where you want to aggregate over it. in you example Year.
In the manual Aggregation option you have to define for each column which aggregation calculation you want to apply (e.g. count, average, minimum, maximum, etc.). You can also define different aggregation calculations for one column.


  1. The processed node is giving me one line of results.
  2. I did read the instructions and found it to be very confusing. Plus i looked through a bunch of videos.
  3. I have 6M rows of crime data variables include year, type of crime, month etc. I am trying to aggregrate the individual rows to get group type of crime by year and month.

Super helpful. Thank you for this.

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