ocr: Invoices Data Mart iime Product ONE: RECORDPER Customer INVOICELNE TEM Promotion Shipper customer communications Data Mart 0 - - Ime ONERECORDPER Product. Customer PROMOTON RESPONSE Promotion Response Combined Data Mart Report Product Promotion Number Total customers Dollar contacted Purchases figure 2. Two data marts with conformed dimensions Time, Cus- tomer, Product, and Promotion). These two data marts can work together to produce a combined report with Product and Promotion as common row headers,