MYSQL选择计数，总和，内部联接和分组依据

Question

SELECT COUNT(s.fid) AS tcount, SUM(t.size) AS tsize, s.uid 
FROM xbt_files_users AS s INNER JOIN torrents AS t 
ON s.fid = t.id 
WHERE s.active = 1 AND s.mtime > '.$time.' AND s.remaining = 0 AND t.size >= 52428800 
GROUP BY s.uid

I have some problems with this query, in busy, some times takes more than 20 seconds ... xbt_files_users is having index for: ARM(active, remaining, mtime), uid, (fid/uid - unique) torrents is having index for size, id primary It`s using:

Using where; Using temporary; Using filesort for xbt_files_users

and

Using where for torrents

It's any way to improve this query?

Answer 1

This is your query:

SELECT COUNT(s.fid) AS tcount, SUM(t.size) AS tsize, s.uid 
FROM xbt_files_users s INNER JOIN
     torrents t 
     ON s.fid = t.id 
WHERE s.active = 1 AND s.mtime > '.$time.' AND s.remaining = 0 AND t.size >= 52428800 
GROUP BY s.uid

The best indexes for these queries are xbt_files_users(active, remaining, mtime, fid, uid) and torrents(id, size) . I would start with those indexes.