# Tag History LastValue interpolation

**URL:** <https://forum.inductiveautomation.com/t/tag-history-lastvalue-interpolation/33639>\
**Category:** Ignition\
**Tags:** ignition80\
**Created:** [April 2, 2020, 6:13pm UTC](https://forum.inductiveautomation.com/t/tag-history-lastvalue-interpolation/33639 "2020-04-02T18:13:04Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![mleefers](https://avatars.discourse-cdn.com/v4/letter/m/8edcca/32.png) [@mleefers](https://forum.inductiveautomation.com/u/mleefers)\
**Post date:** [April 2, 2020, 6:13pm UTC](https://forum.inductiveautomation.com/t/tag-history-lastvalue-interpolation/33639/1 "2020-04-02T18:13:05Z")

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Hello,

I am getting some interesting results using tag history LastValue aggregation mode while allowing interpolation. Here is a screenshot of the database query for the tag.

 ![DatabaseQuery](https://us1.discourse-cdn.com/inductiveautomation/original/2X/9/9f0ccceefc08c9eb0162907fdd58eb3e075bd455.png)

As you can see, there is a value of 0 recorded on 03/23/2020 around 7:30pm and the next value comes in the next day at 9:50 am. Now, when we query the tag history using a 1 minute interval with interpolation enabled, we get the following result.

 ![BeginningOfTagHistory](https://us1.discourse-cdn.com/inductiveautomation/original/2X/7/7205119c65af060422fdfdd18b68bc927c96c08b.png)  
 ![TrueStartUpEvent](https://us1.discourse-cdn.com/inductiveautomation/original/2X/d/d8e1062fff6dff97933073b52e4b7415d51a12fe.png)

It looks like the interpolation is continually accumulating a value for that tag. I would expect for the interpolation to continue to simply use the last known value recorded in the DB. Am I miss interpreting this or is there another way to achieve what I have described?

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<div class="post-metadata">

**Author:** ![Shawn\_Rieger](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/shawn_rieger/32/46336_2.png) [@Shawn\_Rieger](https://forum.inductiveautomation.com/u/Shawn_Rieger)\
**Post date:** [May 1, 2023, 3:27pm UTC](https://forum.inductiveautomation.com/t/tag-history-lastvalue-interpolation/33639/2 "2023-05-01T15:27:34Z")

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Was this ever resolved or figured out?