Re: How to speed up min/max(id) in 50M rows table?

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On Friday 12 October 2007, henk de wit <henk53602@xxxxxxxxxxx> wrote:
> >   select payment_id from transactions order by payment_id desc limit 1;
>
> This one is indeed instant! Less than 50ms. In my case I can't use it for
> max though because of the fact that payment_id can be null (which is an
> unfortunate design choice). The other variant however didn't become
> instant. I.e. I tried:
>
> select time from transactions where payment_id = 67 order by time asc
> limit 1;
>
> But this one is still really slow.

If you had a compound index on payment_id,time (especially with a WHERE time 
IS NOT NULL conditional) it would likely speed it up.


-- 
Ghawar is dying


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