My company currently uses CSV files along with Excel (Pivot Tables) as a reporting instrument. We export CSV from our invoicing system (which is based on MSSQL, so we have MSSQL Server running, just a note).
Time has come for some upgrade because annual base is already 1 million rows. Excel can only import 1 million rows and slows down on some operations at that amount.
I want to have an OLAP Server so that users (approx 10 people) can connect directly from Excel to that server and create Pivot Tables without hassle.
Preferably free/opensource solution.