> ## Documentation Index
> Fetch the complete documentation index at: https://docs.coreweave.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Select Columns

> Remove selected columns from a dataset or keep only the selected columns.

## Description

With this function you can either remove selected columns from a dataset or only keep the selected columns.

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## Application

If you have many columns and don't use all of them it can make sense to reduce the dataset to the columns you need to work with. That is usually beneficial in terms of performance and also makes handling of the data easier.

As an example, if you have hundreds of channels from a certain measurement but only need to work on 20 of those channels reducing the dataset to only those 20 channels would improve performance a lot when working with the dataset.

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## How to use

* Select the dataset to work on in the field **Data**.
* Select the **Columns** to keep or remove from the dataset.
* From the option **Keep or Remove selected columns** select one of the two options:\
  **Keep selected columns**The resulting dataset will only consist of the selected columns**Remove selected columns**The resulting dataset will consist of all columns but the selected ones.
* You can save the resulting dataset under a new name. Enable **Save output under different name** to do so. If that option is unticked the existing dataset will be overwritten.
* Click **Apply** to run the dataset restructuring.

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## More on this step

This step works based on column names. In case you change a selected dataset so that a column can't be found (for example, column name changed or column removed for some reason) the step will error out. To fix the error you have to edit the step and assign new **Columns**. Alternatively, delete the step and create a new one.