I have a SP2010 site that is using a SQL Report (and Report Viewer Web Part) to aggregate and display data from multiple SharePoint lists, all on that same site. The report does not connect to any external database source, only the SharePoint lists.
I am supposed to move the site to SP2013, which, for the lists themselves, is straightforward enough.
However there has also been a request for me to see if I can somehow improve on the report. It does seem to be a bit slow and clunky.
So my question is - in SP2013, is there a better way to aggregate and display data from multiple SharePoint lists (considering no external data source is involved)?