What are the details of all the master customers?
select cmi_details from customer_master_index
Show me the id of one with details 'Gottlieb, Becker and Wyman'.
select master_customer_id from customer_master_index where cmi_details = 'Gottlieb, becker and Wyman'
Show me the distinct cross reference source system codes related to it.
select distinct t2.source_system_code from customer_master_index as t1 join cmi_cross_references as t2 on t1.master_customer_id = t2.master_customer_id where t1.cmi_details = 'Gottlieb, becker and Wyman'