Question

我在以下查询中有两个问题

当我尝试运行查询时，我在oracle中收到以下错误
性能问题，即当我运行没有IN子句的查询时，即在下面的查询中删除{select * from cand_profile where postal_code in}，它需要15秒。如何微调这个SQL查询？

查询

select *
from cand_profile 
where postal_code in (
    SELECT ZIP
    FROM (
        SELECT
            dest.ID,
            dest.postal_code AS ZIP,
            ACOS(SIN(RADIANS(src.latitude))*SIN(RADIANS(dest.latitude))+COS(RADIANS(src.latitude))*COS(RADIANS(dest.latitude))*COS(RADIANS(src.longitude)-RADIANS(dest.longitude)))* 3959 AS DISTANCE
        FROM post_codes dest
            CROSS JOIN
        post_codes src
        WHERE src.ID = (
            SELECT ID
            FROM post_codes
            WHERE postal_code = '60195'
            GROUP BY ID
        ) 
        AND ( dest.ID <> src.ID OR  dest.ID = src.ID )
    )
    GROUP BY ID,ZIP,DISTANCE
    HAVING DISTANCE <= 5
    ORDER BY DISTANCE
))

ORA-00907：缺少右括号   00907. 00000 - “缺少右括号”   *原因：
  *操作：

Answer 1

'in'子句往往效率很低。我会尝试使用连接：

select c.*
from cand_profile c
join (
    SELECT ZIP
    FROM (
        SELECT dest.ID,dest.postal_code AS ZIP, ACOS(SIN ( RADIANS( src.latitude) ) * SIN ( RADIANS ( dest.latitude )) 
+ COS ( RADIANS ( src.latitude)) * COS ( RADIANS ( dest.latitude )) * COS ( RADIANS( src.longitude ) - RADIANS ( dest.longitude ))) * 3959
AS DISTANCE
        FROM post_codes dest
            CROSS JOIN
        post_codes src
        WHERE src.ID = (
            SELECT ID
            FROM post_codes
            WHERE postal_code = '60195'
            GROUP BY ID
        ) 
        AND ( dest.ID <> src.ID OR  dest.ID = src.ID )
    )
    GROUP BY ID,ZIP,DISTANCE
    HAVING DISTANCE <= 5
    ORDER BY DISTANCE
) a
on postal_code = a.ZIP

SQL查询性能问题子查询和缺少括号

1 个答案: