sql - sql server 获取结果延迟的问题如何解决？

Question

我创建了以下视图，

SELECT     
   currency_cd, SUM(comprate) AS salary, employee_code,
   (SELECT SUM(c.comprate) AS Expr1
    FROM dbo.employees_compensation AS c 
    INNER JOIN
       (SELECT MAX(id) AS id, comp_ratecd
        FROM dbo.employees_compensation
        WHERE (effdt = (SELECT MAX(effdt) AS Expr1
               FROM dbo.employees_compensation AS employees_compensation_1
               WHERE (employee_code = b.employee_code)
              )
       ) AND (employee_code = b.employee_code)
    GROUP BY 
       comp_ratecd) AS a ON c.id = a.id) AS salary1
FROM 
   dbo.employees_compensation AS b
GROUP BY 
   currency_cd, employee_code

它工作正常并给出了预期的结果。但问题是执行和给出结果需要时间。有时它也会给出错误，比如超时等。你能帮我解决这个问题吗？

Answer 1

也许你应该重组你的数据库？例如，创建将表示连接的表。如果您不关心时间，您可以通过创建临时表或虚拟表（也称为视图）来避免超时错误。避免这样复杂和嵌套的表达式。