Filter using a separate dimension table

Hello,

         Tableau is good at turning a dataset into a Pivot based matrix with functionality to filter by any of the dimensions from within that dataset.

         In my case, this dataset is HUGE (5 dimensions with 55+M rows) and our company mandates Tableau to access data live from the database.

        Our Tableau dashboard uses independent filters from this dataset and on load of this dashboard, it will issue multiple queries to the database to pull in the unique list of values for the said 5 dimensions. This places lot of load on the database and this table when multiple users are accessing this dashboard simultaneously. Note: The table is already tuned.

        Question - How to solve this performance issue?

        Since I am using independent filters, I could potentially get a unique list of values for these 5 dimensions and load them into a dimension table and then get Tableau to load the filter values from this table and use them to filter data from the main table.

        I have attached an example tableau dashboard which uses cars (Make, Color) as an example.

        The main dataset is in table "Main Table" while the unique values for make and color are in table "Keys".  I am hoping to have all unique values for these 5 dimensions in one table to avoid creating 5 different dimension tables, which would inturn require 5 different DB connections to access each of those tables separately..

        Sheet "Main Table" uses data from the main table to filter on itself. This works great for filters AUDI / BLACK.

        Sheet "w/ dedicated dim table" is an attempt to use data from "Keys" dimension table to filter data from "Main Table" . But is unable to filter properly on AUDI / BLACK. How to solve this?

Thanks.