# Tag historian data pre-processing experiences

**URL:** <https://forum.inductiveautomation.com/t/tag-historian-data-pre-processing-experiences/87236>\
**Category:** Ignition\
**Created:** [March 13, 2024, 12:03am UTC](https://forum.inductiveautomation.com/t/tag-historian-data-pre-processing-experiences/87236 "2024-03-13T00:03:01Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Mitchell\_Dennis](https://avatars.discourse-cdn.com/v4/letter/m/59ef9b/32.png) [@Mitchell\_Dennis](https://forum.inductiveautomation.com/u/Mitchell_Dennis)\
**Post date:** [March 13, 2024, 12:03am UTC](https://forum.inductiveautomation.com/t/tag-historian-data-pre-processing-experiences/87236/1 "2024-03-13T00:03:01Z")

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Hey all,

Was wondering if anyone has had any experience with using the tag historians pre-processed partitions and whether or not that has had any impact or value.

In my own experience, with a window size of 60s, it has more than doubled the space requirements.  
For one partition, the raw table is 44GB, and the pre-processed partition is 66GB.  
On another partition, the raw is 39GB, and the pre-processed is 55GB.

In terms of performance though, the queries seem slightly faster?  
I can query 3 tags for 3 months of data in less than 5 minutes.  
Not sure how best to quantify and measure that.

So currently I'm tossing up whether I want to implement my own post-processing so users can quickly query months / years at a time.

What have your experiences been?