However (just to be picky) pushing the WHERE clause into the FROM statement to me implies structuring this SQL statement:

SELECT c.city_name, c.population, b.business_name
FROM up_city c LEFT OUTER JOIN up_business b
ON c.city_name = b.city_name
WHERE c.population >= 5000;

to something like this:

SELECT c.city_name, c.population, b.business_name
FROM ( select *
from up_city
where c.population >= 5000
) c LEFT OUTER JOIN up_business b
ON c.city_name = b.city_name;

In principle if the SQL is processed according to the conceptual model then the filtering should take place before the join is performed.

Adrian Miley