What is the basic relationship between measures and dimensions in transformer modelling?
Measures are the quantifiable HOW MANYs that measure business performance (e.g. units, revenue, cost)
Dimensions are the WHO/WHERE/WHEN/WHATs which describe and qualify that performance (e.g. product, customer, salesperson, location). They tend to be but are not necessarily hierarchical in nature.
They are related by the transactions or fact data captured as the business conducts its operations.
...more specific to your question, in Transformer modelling measures and dimensions are related in a fact query. The fact query should include at least the lowest level values for your dimensions, and may be supported by additional dimensional queries containing the dimensions' levels. The relationship between the fact and dimensional queries in Transformer is determined by the names of the lowest level data items.