In my experience, you rarely want to fully normalize your data (unless it's
something simple). City and country codes I wouldn't split up because they
never change. Well, alright, there have been quite a few new "countries"
popup in Europe recently. But you don't need to change hundreds or thousan
>
To: <[EMAIL PROTECTED]>
Cc: "andy" <[EMAIL PROTECTED]>
Sent: Monday, May 20, 2002 4:01 PM
Subject: RE: Join takes way too long. Query optimizing, or denormalizing?
> * andy
>
> > > > SELECT count(DISTINCT user_recommending)
> > > > FRO
* andy
> > > SELECT count(DISTINCT user_recommending)
> > > FROM recommendations t
> > > INNER JOIN geo.cities AS c ON t.city_id = c.ID AND
> > > c.country_code = 'gm'
> I guess this is not an issue on the index. Explain select says it is using
> the index. So I assume, that I did just write dow
I guess this is not an issue on the index. Explain select says it is using
the index. So I assume, that I did just write down the join syntax wrong.
MySQL is joining all 32000 records with the city table and then looks for
the country code. So this looks ok to me. Maybe I should denormalize my dat
