我编写了一个脚本,执行大约需要 15 个小时。我需要一些查询优化技术或建议以使此脚本尽可能快...如果有人可以提供帮助,请查看脚本:
declare @max_date date
declare @client_bp_id int
Select @max_date=MAX(tran_date) from All_Share_Txn
DELETE FROM Client_Share_Balance
DECLARE All_Client_Bp_Id CURSOR FOR
SELECT Bp_id FROM Client --Take All Client's BPID
OPEN All_Client_Bp_Id
FETCH NEXT FROM All_Client_Bp_Id
INTO @client_bp_id
WHILE @@FETCH_STATUS = 0
BEGIN
Insert Client_Share_Balance(Bp_id,Instrument_Id,Quantity_Total,Quantity_Matured,Quantity_Pledge,AVG_Cost,Updated_At,Created_At,Company_Id,Created_By,Updated_By)
select @client_bp_id,Instrument_Id,
sum(case when Is_buy='True' then Quantity when Is_buy='False' then -quantity end), --as Total Quantity
sum(case when Mature_Date_Share <= @max_date then (case Is_buy when '1' then quantity when '0' then -quantity end) else 0 end), --as Free Qty
ISnull((select sum(case pu.IsBuy when '1' then -pu.quantity else pu.quantity end) from
(Select * from Pledge UNION Select * from Unpledge) pu
where pu.Client_Bp_id=@client_bp_id and pu.Instrument_Id=t1.Instrument_Id and pu.Txn_Date<=@max_date
group by pu.Client_Bp_id,pu.Instrument_Id),0), -- as Pledge_Quantity
dbo.Avg_Cost(@client_bp_id,Instrument_Id), --as Avg_rate
GETDATE(),GETDATE(),309,1,1
from All_Share_Txn t1
where Client_Bp_id=@client_bp_id and Instrument_Id is not null
group by Instrument_Id
having sum(case Is_buy when '1' then quantity when '0' then -quantity end)<> 0
or sum(case when Mature_Date_Share <= @max_date then (case Is_buy when '1' then quantity when '0' then -quantity end) else 0 end) <> 0
FETCH NEXT FROM All_Client_Bp_Id
INTO @client_bp_id
END
CLOSE All_Client_Bp_Id
DEALLOCATE All_Client_Bp_Id
只需要验证代码是否可以更有效地编写..