-- @(#)8a.sql	2.1.8.1

-- TPC-H/TPC-R National Market Share Query (Q8)

-- Variant A

-- Approved February 1998

:x

:o

select
	
	o_year,

	sum(decode(nation, ':1', volume, 0)) / sum(volume) as mkt_share

from
	(

	select
			
		extract(year from o_orderdate) as o_year,
					l_extendedprice * (1-l_discount) as volume,
					n2.n_name as nation
		
	from

		part,
		
		supplier,
	
		lineitem,
	
		orders,
		
		customer,
		
		nation n1,
		
		nation n2,
		
		region
		
	where
			
		p_partkey = l_partkey
			
		and s_suppkey = l_suppkey
			
		and l_orderkey = o_orderkey
			
		and o_custkey = c_custkey
			
		and c_nationkey = n1.n_nationkey
			
		and n1.n_regionkey = r_regionkey
			
		and r_name = ':2'
			
		and s_nationkey = n2.n_nationkey
			
		and o_orderdate between date '1995-01-01' and date '1996-12-31'
			
		and p_type = ':3'
	
	)	all_nations

	group by
	
		o_year
	order by

		o_year;

:n -1