Views Performance Issue, 7 millions records

Hi,

I have three views in the DWH. Each view takes approx. around 3 minutes to generate the results. Additionally each view generates 7 millions records. These views are affecting my SSAS cube performance in some or other way.

I have tried many options like using CTE instead of distinct, replace coalesce with isnull and replacing older-style inner joins to regular inner joins. Nothing is helping me to speed up the views. Also the views has 4 blocks of union all. Each block of query runs fine on themselves but when I run the whole view it is very slow as explained above.

Do you have any ideas of how to speed up this or start analysing the issue behind these view?

Regards.
sssqllearner.