SQL执行效率问题
44万数据测试 
两个存储过程内容如下:
1、
select note from table where cityID='1'
2、
WITH temp AS
(
SELECT * FROM city WHERE cityid=1
UNION ALL
SELECT city .* FROM city
INNER JOIN temp ON city .professionParent=temp.cityid
)
SELECT table .note FROM table
INNER JOIN temp ON table .cityid=temp.cityid
那个执行速度最快
两个存储过程内容如下:
1、
select note from table where cityID='1'
2、
WITH temp AS
(
SELECT * FROM city WHERE cityid=1
UNION ALL
SELECT city .* FROM city
INNER JOIN temp ON city .professionParent=temp.cityid
)
SELECT table .note FROM table
INNER JOIN temp ON table .cityid=temp.cityid
那个执行速度最快
 
                    
                     
                    
                 
                    
                 
 
                
            
         
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浙公网安备 33010602011771号