Slow loading of Historical Easy Chart

Hi all,

since our update from 7.9 to 8.1 I have a really big problem with performance regarding easy_chart components. I have a standard timeseries chart, the SQL Query for which takes approx. 200ms and the easy_chart in realtime configuration takes not much longer then that to load all the data. The chart in historical configuration however takes over 45 seconds to load the same data as the first 2 mentioned options.

Here you can see the entry from the Longest Recent Queries page:

t_stamp, TemperaturOberflaeche, WalzenspaltMittelwert, DruckLinks, DruckRechts, GeschwindigkeitUnterwalze, WalzenspaltLinks, WalzenspaltRechts, iif(Betriebszustand=5,1,0), iif(Betriebszustand=3,1,0), iif(Betriebszustand=2,1,0), iif(Betriebszustand=4,1,0), iif((Betriebszustand=0 or Betriebszustand=1),1,0) 
t_stamp >= ? AND t_stamp <= ? ORDER BY t_stamp

Does anyone have an idea why there could be such a massive difference in loading times?

I’m running version 8.1.7 on Windows Server 2016 64-Bit and Microsoft SQL Server 2017

My CPU usage normally is between 1 and 5% and my RAM usage is about a fourth to a third of the total allocated space.

Thanks in advance!