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Sql 查询解决方案很慢_Sql_Sql Server_Inner Join - Fatal编程技术网

Sql 查询解决方案很慢

Sql 查询解决方案很慢,sql,sql-server,inner-join,Sql,Sql Server,Inner Join,我有一个疑问: select t1.IMMAGINE as r1 , t1.NOME as r2, t1.IMO as r3 from FOTO_NAVI.dbo.NAVI as t1 INNER JOIN ( select distinct t3.IMO from ( select I_ID_NAVE,

我有一个疑问:

select          
   t1.IMMAGINE as r1 ,
   t1.NOME as r2,
   t1.IMO as r3
from
   FOTO_NAVI.dbo.NAVI as t1 
   INNER JOIN 
   (
       select 
           distinct t3.IMO
       from 
       (
           select 
               I_ID_NAVE,
               D_PREVISTO_ARRIVO,
               I_ID_PORTO               
           from 
               Olbia.dbo.ESTERNALIZZAZIONE_FASCICOLINAVE as tint
           where
               tint.D_EFFETTIVO_ARRIVO IS NULL and
               tint.D_PREVISTO_ARRIVO>GETDATE()-1 AND            
               tint.I_ID_PORTO=42104    
       )as t2
       inner join OLbia.dbo.NAVI as t3      
           on t3.N_ident_seguenziale=t2.I_ID_NAVE
  ) AS T4
      on T4.imo= t1.imo
order by t1.IMO

嗨,伙计们,这实在太慢了,你们能让它快点吗?速度问题我认为t4和t1之间的连接没有更多细节,只能给出一般性的想法:

  • 查看查询计划和统计io输出。这会告诉你问题出在哪里
  • 最有可能的情况是,您丢失了一个或几个索引,并在大表上执行扫描,或者您甚至可能因此而有一个假脱机
  • 根据选择性,部分或全部这些可能应该被索引:D_EFFETTIVO_ARRIVO、D_PREVISTO_ARRIVO、I_ID_PORTO
  • 对于联接,请检查OLbia.dbo.NAVI.N_ident_seguenziale和FOTO_NAVI.dbo.NAVI.imo的索引

如果这些都没有帮助,请编辑此问题或询问包含表结构、索引、查询计划和统计io输出的新问题。

如果是英文,请使用该语言
mysql
sql server
对于不同的DBMS来说是不同的。是mysql还是sql server速度较慢?(两种不同的产品,使用稍微不同的优化技术)jQuery在这个查询中做什么?