Re: Make this faster?

[Toa Sty]

Even if you don't specify an order by clause you'll often still see a filesort when grouping. You can sometimes specify 'order by null' to skip this sort. It might help. If it's using an index fully you should not need to do this though, so I suspect you're not fully using an index.

BTW It'd help a bit if you could post the show create table and explain each time, for example, if you've created the multi-col index on (month, year) but you're grouping by year,month it won't use the index.


My suspicion is that you'll see best performance if you create a multi-col index on (md5_key, red_year, red_month). If it's working as I expect you won't see a filesort when you explain.

Toasty

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