Optimisation - Context transition in iterator

Hi mark_endicott 

Can you try the following :

VAR CurrentInterval =

    SELECTEDVALUE ( 'RLS CALENDAR'[LEVEL_1_END_DATE] )

VAR StartDate = 

    SELECTEDVALUE( 'RLS CALENDAR'[YEAR_START_DATE] )    

VAR Grain =

    SELECTEDVALUE ( 'RLS CALENDAR'[LEVEL_1_GRAIN] ) 

VAR Selected_Territory = 

    SELECTEDVALUE ( 'RLS CALENDAR'[TERRITORY_CODE] ) 

VAR calculate_volume = 

    CALCULATE (

        [Total volume],

        FILTER (

            ALL ( 'RLS CALENDAR' ),

            'RLS CALENDAR'[LEVEL_1_END_DATE] > StartDate

                && 'RLS CALENDAR'[LEVEL_1_END_DATE] <= CurrentInterval

                && 'RLS CALENDAR'[LEVEL_1_GRAIN] = Grain

                && 'RLS CALENDAR'[TERRITORY_CODE] = Selected_Territory

        )

    )

RETURN

    calculate_volume

===============OR===================

VAR CurrentInterval =

    SELECTEDVALUE ( 'RLS CALENDAR'[LEVEL_1_END_DATE] )

VAR StartDate = 

    SELECTEDVALUE( 'RLS CALENDAR'[YEAR_START_DATE] )    

VAR Grain =

    SELECTEDVALUE ( 'RLS CALENDAR'[LEVEL_1_GRAIN] ) 

VAR Selected_Territory = 

    SELECTEDVALUE ( 'RLS CALENDAR'[TERRITORY_CODE] ) 

RETURN

    SUMX (

        FILTER (

            ALL ( 'RLS CALENDAR' ),

            'RLS CALENDAR'[LEVEL_1_END_DATE] > StartDate

                && 'RLS CALENDAR'[LEVEL_1_END_DATE] <= CurrentInterval

                && 'RLS CALENDAR'[LEVEL_1_GRAIN] = Grain

                && 'RLS CALENDAR'[TERRITORY_CODE] = Selected_Territory

        ),

        [Total volume]

    )

The above two expressions calculate the Total volume measure outside of the iteration and place it in a variable. These should help improve performance by reducing the number of iterations required to calculate the expression.

You can read Marco Russo's article on optimizing DAX expressions:

https://www.sqlbi.com/articles/optimizing-dax-expressions-involving-multiple-measures/

Please let me know if this help.

Thanks

Babatunde Dallas