Formulas for Grand Totals in Saiku

Hello,

I am creating a Mondrian Cube and using it in a Saiku Analytics Report.

I use the option in Saiku to add a Grand Totals row. This works fine for all the columns which are summable. However, there are columns for which I want to tell the system not to apply the sum but in the case of a sum row, apply the row-wise formula.

For example the below table shows a Ratio% column which is ColumnA / ColumnB as a percentage. When I apply the Grand Total row using the Sum aggregation, I get the sum of the percentages as shown in **red** below.

Session |
ColumnA |
ColumnB |
Ratio% |

A |
56 |
57 |
98,25% |

B |
40 |
45 |
88,89% |

C |
32 |
42 |
76,19% |

**Total** |
**128** |
**144** |
**263,32%** |

How can I tell the schema or Saiku that in case of a Totals row being added, that column should not be summed up but it should rather apply the formula applied to the calculated member?

Thanks in advance.