I'm currently experiencing an issue when using the Easy Charts to populate Tag History trends. Our current partition size for the historian is 12 hours of data and will contain approximately 50 million rows. We are also exclusively using Easy Charts with Tag Pens to query the historian to populate trends. The issue we are encountering is that when more than one pen is used for an extended time period (+14 days) the query will often take a long time or timeout entirely if 3 or more pens are used. However, when only one pen is used the query will execute quickly, typically within seconds.
I understand we have quite a bit of data being stored, and this is likely the issue with the slow queries. I'm not sure how the Easy Chart executes the queries for multiple pens, but I was wondering if there may be a configuration I'm missing that might improve the query speed since 1 pen is ~2s to query, 2 pens jumps to ~20s to query and 3 or more will often timeout. It seemed a little odd to me that one pen will populate quickly then it slows down quite drastically but again I'm not very familiar with how the queries are executed.
Any input would be appreciated,
Thanks!