slow performance on applying totals for multiple blocks in a column

[kiran.timsina]

I have multiple metrics in multiple blocks in the same column and I need to show totals. I can't apply sub-totals/total by normal grouping and aggregation. So, first I applied total just for once metric in a column, then I created metrics (around 70) for the sub-totals/total and then I dragged those metrics into multiple blocks of total. This solves my problem, but the report takes 3 to 4 times longer to run than the report without sub-totals/total. Any suggestions to reduce the run time with totals?