Charts not getting data from performance wherehouse, only from session storage. If you think about extracting raw data from PW, i don't think it is possible and good idea. Those data are encrypted I think.
I do not need the raw data.
I need to visualize the number of visits over time taken from the performance warehouse, not the session storage.
For example I would like to show the trend of users hitting the website which count as UEM visit for a period of one month, six months, etc.
Is there built in way or I need to create specific BT instead?
Such metrics are stored in Performance Wherehouse, but over time aggregation is changing. You don't need business transaction for this. If you are talking about count of visits, this will be served from PW, not from session storage. This is why results are serving fast.