Create an Analytic / Reporting Page using Opensource BI -- 2

We need to create a sub site of our website that will show customers data in pivots table, dashboards, etc. More like analytical/OLAP page for our customer. We have relational database in Postgres 9.6 that will be the source of this. The goals: 1. To have independent web page that can be accessed by our customer. 2. There are at least 3 pivots view that we want to show our customers: - Inventory (SKU, Transaction No, Date, Day, Month, Year, Qty, Location) - Sales (SKU, Category, Transaction No, Date, Day, Month, Year, Price, Disc, Tax, Margin, Qty, Location, Customer, Cogs, Amount, Channel) - Customer (Transaction No, Date, Day, Month, Year, Amount, SKU, Channel, City, Province, Country) 3. It must be a server side processing. We dont want to bring millions of records to the clients. 4. The tools used must be an open source. Perhaps Pentaho? or any other tools that is not expensive 5. As a note, we use Azure to host this web page. So take it as your consideration You must have experience building this kind of system. We need to see your past project on this.