# How "File Reader" works?

**URL:** <https://forum.knime.com/t/how-file-reader-works/46677>\
**Category:** KNIME Analytics Platform\
**Created:** [September 2, 2022, 4:40am UTC](https://forum.knime.com/t/how-file-reader-works/46677 "2022-09-02T04:40:02Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![jjlee](https://forum-cdn.knime.com/letter_avatar_proxy/v4/letter/j/8baadc/32.png) [@jjlee](https://forum.knime.com/u/jjlee)\
**Post date:** [September 2, 2022, 4:40am UTC](https://forum.knime.com/t/how-file-reader-works/46677/1 "2022-09-02T04:40:02Z")

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Hi all,

How does the file reader node work?  
When data is read from the file reader node, how is the data stored?  
Are they temporarily saved when the workflow is executed and deleted when the workflow is closed?  
I would like to know where the temporary directory is stored, etc.

I searched for this, but couldn’t find anything other than setting options. If you know anything please let me know.

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**Author:** ![mlauber71](https://forum-cdn.knime.com/user_avatar/forum.knime.com/mlauber71/32/73590_2.png) [@mlauber71](https://forum.knime.com/u/mlauber71)\
**Post date:** [September 2, 2022, 5:16am UTC](https://forum.knime.com/t/how-file-reader-works/46677/2 "2022-09-02T05:16:50Z")

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@jjlee in general when a KNIME node has a green traffic light the underlying data will be stored with the workflow:

> [@jjlee](#):
>
> I would like to know where the temporary directory is stored

You could take a look at this thread:

> [@Question about 'Memory Policy' in node options.](https://forum.knime.com/t/question-about-memory-policy-in-node-options/36839/2):
>
> @pigret113 welcome to the KNIME forum. The data will be stored in a temporary location you could see by using the [Extract Context Properties](https://hub.knime.com/knime/extensions/org.knime.features.base/latest/org.knime.base.node.io.extractcontextprop.ReadContextProperty2NodeFactory) node under the value “context.workflow.temp.location”. You could actually change that temporary location of you wish to do so: Also if you must you could tweak the internal storage of the data, as well as use the (new and still experimental) [columnar storage in Apache Parquet](https://www.knime.com/blog/improved-performance-with-new-table-backend). But You should be careful to do that. A smal…

Then you might want to take a look at the workbench guide our of [KNIME’s excellent documentation](https://docs.knime.com/?category=analytics_platform&version=latest):

[https://docs.knime.com/latest/analytics\_platform\_workbench\_guide/index.html](https://docs.knime.com/latest/analytics_platform_workbench_guide/index.html)

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**Author:** ![system](https://forum-cdn.knime.com/uploads/default/original/1X/ab3ccf34482a0329361734a18199390177204f15.png) [@system](https://forum.knime.com/u/system)\
**Post date:** [September 9, 2022, 5:17am UTC](https://forum.knime.com/t/how-file-reader-works/46677/3 "2022-09-09T05:17:48Z")

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