Question

我有以下需要帮助的查询。

SELECT a.artist, a.facepic
FROM artists_vs AS v, artists AS a 
WHERE v.genreid =0 
AND (v.artistid1 = a.artistid OR v.artistid2 = a.artistid)
ORDER BY v.bid DESC 
LIMIT 20

查询中的所有字段都被编入索引，但是当我运行解释时，我得到以下内容：

1   SIMPLE  v   ref genreid,artistid1,artistid2 genreid 4   const   15  Using temporary; Using filesort
1   SIMPLE  a   ALL PRIMARY NULL    NULL    NULL    18165   Range checked for each record (index map: 0x1)

我需要在my.cnf

中启用log-queries-not-using-indexes

有人可以建议我如何重写此查询以使其远离慢速日志吗？

Answer 1

你可以尝试这样的事情：

SELECT 
    a.artist, 
    a.facepic,
    V.bid
FROM artists_vs AS v
inner join artists as a on v.artistid1 = a.artistid
WHERE v.genreid = 0 
union
SELECT 
    a.artist, 
    a.facepic,
    v.bid
FROM artists_vs AS v
inner join artists as a on v.artistid2 = a.artistid
WHERE v.genreid = 0 
ORDER BY bid DESC 
LIMIT 20

如何从mysql_slow.log中保留这样的查询？

1 个答案: