我是 XQuery 的新手。请提出一种优化以下查询的方法。
我已经尝试过以下查询,它花费的时间比预期的要多。
Select
A.a_name,
I.p_type,
SUM(P.c_n_amount) AS c_n_amount,
CASE WHEN SUM(ABS(M_value)) = 0 THEN 0
ELSE SUM(ABS(Price) * ABS(M_value)) / SUM(ABS(M_value)) END AS
[price],
SUM(M_value) AS m_value,SUM(N50) [-50],SUM(P50) [50]
from position P
INNER JOIN COUNT AS A ON P.a_id = A.a_id
INNER JOIN I_VIEW AS I ON P.i_id = I.i_id
inner join (
select R_C.p_id,M_value,Price,N50,P50
from(
select j.p_id,
C.value('(Result[@resultName = "m_value"]/resultValue)[1]', 'float') as M_value,
C.value('(Result[@resultName = "price"]/resultValue)[1]', 'float') as Price
from jyothi_xml j CROSS APPLY resultkeys.nodes('/Results') T(C)
where r_set='POLY' and r_category ='sk') R_Category,
(select j1.p_id,
C.value('(Result[@resultName = "rate_shock_n50"]/resultValue)[1]', 'float') as N50,
C.value('(Result[@resultName = "rate_shock_p50"]/resultValue)[1]', 'float') as P50
from jyothi_xml j1 CROSS APPLY resultkeys.nodes('/Results') T(C)
where result_set='POLY' and result_category ='rate_shocks') R_S_Category,position p
where p.p_id=R_Category.p_id and p.p_id=R_S_Category.p_id) XMlData on p.p_id=XMlData.p_id
WHERE P.as_of_date = '2012-10-10'
GROUP BY A.a_name, I.p_type