Its a work in progress, so its the best i have so far.

What is interesting is that Microsoft DBA's could not even get the query quicker than 5 seconds !

The more i used normalization, the slower the query performed, so it has gradually been denormalized, to improve performance.

The senior DBA's had over 15 yrs experience, and worked for Fortune 500 companies, managing databases with many Terabytes of data, so they could not have been that bad.

Either way, thanks for your feedback 🙂