Yesterday all of my analysis were working fine. Today, when I went to look, most (maybe all) are failing with the error shown below. Any thoughts on where I should look?
Analysis backfilling only works if output is mapped to PI Points. Looks like you have mapped AF attitude which is not a PI point.
Outputs mapped to attributes which are not PI points will calculate dynamically based on inputs.
To add to that: having analysis output to a non-PI-Point attribute can cause significant load on the SQLserver. This is generally NOT advised (read: a big NO-NO in the best practices). A general exception is when no history is saved, then this results in an Analysis DataReference being set on the attribute.
About the best practices here: KB01641 - PI Analysis Service Best Practices
More about the Analysis DR here: KB01586 - The Analysis Data Reference: Use Case, Configuration and Caveats
To add to what the others replied; I've seen this myself. The analysis did work as expected, perhaps even with backfilling/recalculation - but suddenly you see this error. The reason turned out to be that I was outputting both historized and non-historized data from within the same expression analysis. I believe I had five calculations being output to PI Point Data Reference attributes and then I introduced a 6th output which I didn't see the need to save history for - as it was only a checksum / data quality check. Upon backfilling I got the same error message, and the solution is either to save the output of this expression to a PI Point as well - or separate this non-historized expression from the rest of the (historized) expression outputs.
If the answers given above don't explain your situation, can you share your Asset Analytics version as well as the configuration of one of those analyses?
Otherwise, can you mark Lal's, Roger's or Asle's reply as correct?
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