Question

我有一个包含26列和超过10 ^ 8行的表，并包含一些股票市场数据。我正在执行一个非常基本的查询，但它并不像我期望的那样高效：

select * from tableA where (cusip_id, mkt_close_dt) in (
               select cusip_id, max(mkt_close_dt) from tableA
               where mkt_close_dt >= '2012-12-25' and mkt_close_dt <= '2013-01-01'
               and cusip_id in ('025081753', '04314H709', '115291833', 
               '086233103', '119530202', '22544R305', '256206103', 
               '256219106', '471023887', '476313101', '471023598', 
               '66537V336', '592905103', '665162400', '779547108', 
               '741481105', '77956H864', '693391682', '779557107', 
               '77957P105', '693390700', '77956H104', '780905709', 
               '784924789', '880208400', '885215566', '779919109', 
               '00141A545', '09256H328', '31429A105', '471023762', 
               '04315J860', '543495840', '592905848', '592905509', 
               '693390130', '921937793', '78464A516', '73935S105', 
               '464287465', '464288281', '464288612', '464288869', 
               '464287630', '464287648', '464287481', '78464A417', 
               '464288588', '464288273', '464287457', '464287176', 
               '922908553', '922908512', '922908744', '922908736', 
               '922042858', '464287226', '921937835', '902641679', 
               '06738C778', '78464A854', '78464A847', '33734K109', 
               '33735B108', '33734Y109', '464288596', '464287507', 
               '464287804', '464287150', '464287200', '464287622', 
               '464287655', '464287499', '464287689', '464287846', 
               '464287127', '464288208', '464288505', '78464A649', 
               '72201R304', '78467Y107', '921910873', '464287135', 
               '464287101', '73935X450', '73935X443', '73935X435', 
               '78355W106', '78463X863', '808524607', '808524102', 
               '808524201', '78464A813', '78462F103', '72201R205', 
               '78464A664', '464287432', '78464A805', '922908751', 
               '921908844', '922908629', '922908413', '922908769', 
               '922908637', '922908652', '18383M498', '78464A490', 
               '78355W205', '921937827', '464288422', '81369Y407', 
               '73935X195', '81369Y605', '81369Y100', '81369Y308', 
               '81369Y506', '81369Y886', '81369Y209', '81369Y704', 
               '81369Y803', '92206C664') group by cusip_id

请注意，我将动态创建cusip_id列表（即，它会不断变化），mkt_close_dt也会有所不同。最后，我也不想使用临时表。鉴于这些限制，我怎样才能提高性能？

Answer 1

考虑到这些条件，您似乎试图从给定cusip_id的最大日期获取记录。

我建议使用窗口函数：

select t.*
from (select a.*,
             max(mkt_close_dt) over (partition by cusip_id) as maxdt
      from tableA a
      where mkt_close_dt >= '2012-12-25' and mkt_close_dt <= '2013-01-01' and
            cusip_id in ('025081753', '04314H709', '115291833', 
               '086233103', '119530202', '22544R305', '256206103', 
               '256219106', '471023887', '476313101', '471023598', 
               '66537V336', '592905103', '665162400', '779547108', 
               '741481105', '77956H864', '693391682', '779557107', 
               '77957P105', '693390700', '77956H104', '780905709', 
               '784924789', '880208400', '885215566', '779919109', 
               '00141A545', '09256H328', '31429A105', '471023762', 
               '04315J860', '543495840', '592905848', '592905509', 
               '693390130', '921937793', '78464A516', '73935S105', 
               '464287465', '464288281', '464288612', '464288869', 
               '464287630', '464287648', '464287481', '78464A417', 
               '464288588', '464288273', '464287457', '464287176', 
               '922908553', '922908512', '922908744', '922908736', 
               '922042858', '464287226', '921937835', '902641679', 
               '06738C778', '78464A854', '78464A847', '33734K109', 
               '33735B108', '33734Y109', '464288596', '464287507', 
               '464287804', '464287150', '464287200', '464287622', 
               '464287655', '464287499', '464287689', '464287846', 
               '464287127', '464288208', '464288505', '78464A649', 
               '72201R304', '78467Y107', '921910873', '464287135', 
               '464287101', '73935X450', '73935X443', '73935X435', 
               '78355W106', '78463X863', '808524607', '808524102', 
               '808524201', '78464A813', '78462F103', '72201R205', 
               '78464A664', '464287432', '78464A805', '922908751', 
               '921908844', '922908629', '922908413', '922908769', 
               '922908637', '922908652', '18383M498', '78464A490', 
               '78355W205', '921937827', '464288422', '81369Y407', 
               '73935X195', '81369Y605', '81369Y100', '81369Y308', 
               '81369Y506', '81369Y886', '81369Y209', '81369Y704', 
               '81369Y803', '92206C664')
     ) t
where mkt_close_dt = maxdt;

SQL（Netezza）查询性能

1 个答案: