问题 Background: I’m doing analysis of call detail record (CDR) data in order to segmentify customer with respect to their call duration, time of call (holiday call or non holiday call, Business call or non Business call), age group of subscriber and gender. Data is from two table name cdr (include card_number, service_key, calling, called, start_time, clear_time, duration column) and subscriber_detail (include subscriber_name, subscriber_address, DOB, gender column) I have design OLAP as given