Normally a measure is computed at the level of detail of the view: one value per mark. A level of detail (LOD) expression sets the level itself.
{ FIXED [Customer Name] : SUM([Sales]) } adds up sales for each customer, whatever is on Rows or Columns. Every order line of a customer carries that customer's total, so you can average it by region or use it to group customers.
Three things to remember:
- The part after the colon must be an aggregation, such as
SUM, MIN or COUNTD.
- The result is row level. A number lands with the measures; to group by it, right-click the pill and choose Dimension.
- FIXED runs before dimension filters, so a filter on Category doesn't change it unless you add that filter to context.
INCLUDE and EXCLUDE set the level relative to the view instead; they come later in the course.