Re: peformance help: preventing 'using temporary; using filesort'

[Sebastian Mendel]

Rich Brant schrieb:
> Is there anyway to prevent the temporary and filesort?
> 
>     SELECT
>     t1.sourceID as sourceID,
>     count(t1.sourceID) as clicks,
>     [...]
>     ORDER BY clicks desc, conversions desc;
> 
> When using EXPLAIN:
> 
> [...] Using where; Using temporary; Using filesort |

when using ORDER BY on a computed row MySQL cannot use any index of course,
you would need an index on COUNT(t1.sourceID) what is not possible

-- 
Sebastian