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RichardBailey-8937 asked RichardBailey-8937 commented

How do I get the most recent good value at a point in time from Time Series Insights?

I cannot find a reliable way to retrieve the most recent good value prior to a given timestamp via the TSI API without recursing the entire history of each point. It looks like the getEvents, getSeries, and getAggregateSeries only ever process data INSIDE the searchSpan, so if you need to find the value prior to a timestamp, you need to put a huge span in place. Since these methods only ever return the first 10k (or 250k) samples ordered from the beginning of the search span, there is no easy way to find the most recent value without progressively recursing back in history until you find a sample.

Is there a way to do this using the various aggregate, boundary, and take: 1 options which doesn't need me to search the entire history of the series?

azure-time-series-insights
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@RichardBailey-8937 Welcome to Microsoft Q&A forum!
Did you check this similar query already? Get Last Value of a Time Series with Azure TimeSeries Insights
I am also checking internally with our team if there is another way. Appreciate your time and patience.

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Yes, but if you don't know what Span to specify then you may not get the last value. A fundamental aspect of every other historian out there is the ability to interpolate start and end boundary values for a given time-range. Some data may not update for years while other data is updating every second. It looks like a large Span causes TSI to actually retrieve that whole span to find the start boundary value and so far this looks slow and potentially expensive if we're doing this type of query a lot (e.g. every minute for a lot of tags) against the cold store.

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Thanks for the additional information. I will update you once I hear back from our team on this query.

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@RichardBailey-8937 Did you get a chance to see below response?
If an answer is helpful, please click on 130616-image.png or upvote 130671-image.png which might help other community members reading this thread.

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@AshokPeddakotla-MSFT Thanks for the feedback. This is disappointing. We are trying to use TSI for industrial process customers in lieu of a traditional on-premise historian. Is Microsoft targeting the industrial historian space with TSI? If so, they need to provide a minimum viable product and boundary interpolation is a big gap in that functionality. If Microsoft need input to understand how industrial historians are used and what is required from them, I'm happy to have a session with the product manager to show how they are used in the real world and what kinds of client tools and usages hang off them.

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1 Answer

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AshokPeddakotla-MSFT answered

@RichardBailey-8937 Apologies for taking too long on this. Currently we don't support this feature.

Also, We would like to inform you that, We have shared this feedback with our Time Series Insights product team and it has been considered for feature request. Please let us know if you have any further queries.


Please don't forget to click on 130616-image.png or upvote 130671-image.png button whenever the information provided helps you. Original posters help the community find answers faster by identifying the correct answer. Here is how

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