> Doesn't seem like count(*) is an essential component of a solution
to
> this problem. What are the available article identifiers and
indexes?
> For example, if you had a timestamp column with an index, you could
> define "a random article" as "the first one after a randomly chosen
> time", which could be retrieved efficiently with
>
> select * from articles where timestamp >= 'targeted time' limit 1;
>
> The target time could be chosen as some random fraction between the
> start of your database and now(). This'd be skewed by variations in
> the rate of article posting, but it'd probably do for your purposes.
>
> If there is a serial number column then it's even easier, since the
> range of article numbers is from 1 to the sequence's last_value.
I think that might work well for me, thanks!
> > I thought I came up with a good solution, now I "select ... from
...
> > order by random() limit 1", which is nice because it only
> requires one
> > query to get what I want but it's still slow.
>
> That is most definitely *not* going to be fast, since it requires an
> explicit sort of all the rows.
Good point :)
Thanks,
Jeff