Re: Query only slow on first run

[cluster <skrald(at)amossen(dot)dk>]

> > I'm wondering why --- doesn't seem like it should take 6400msec to fetch
> > 646 rows, unless perhaps the data is just horribly misordered relative
> > to the index.   Which may in fact be the case ...

Hmm, actually I still don't understand why it takes 6400 ms to fetch the 
rows. As far as I can see the index used is "covering" so that real row 
lookups shouldn't be necessary. Also, only the the random_numbers 
induces by questions with status = 1 should be considered - and this 
part is a relatively small subset.

In general, I don't understand why the query is so I/O dependant as it 
apparently is.