I have a project containg some pages showing trend from the historian.
These pages are very popular so it is shown on multiple client.
My problem is it seems to keep the SQL server pretty busy. How should I optimize that?
Could I have a dataset on the gateway containg the data from the historian and then show the dataset in the client? Or any other idea to avoid multiples client to query the same data from the historian?
Thanks a lot.
If you are using named queries, there’s automatic caching is the substitution parameters match. When using a datetime window, I recommend rounding start/end timestamps to fixed intervals to maximize the chance the cache will have the data. At least, truncate milliseconds for real-time charting purposes.
The tag historian does some caching, too, but that is rather opaque. If you need caching for Vision’s EasyChart DB pens, I strongly recommend my own solution: NoteChart and TimeSeriesDBCache modules.