On 2/17/2013 2:09 PM, Tim Uckun wrote:
Say I created new columns on both tables called "first_6" and populated them with the substrings. If I did a inner join or a left join on those fields would I still get a cross join? inner join model_configurations mc on mc.first_6 = crm.first_6
without additional filtering, that will return a row for every row in crm that matches a row in mc. if there's a 1000 rows in crm that each match an average of 6 rows in mc, that would return 6000 rows.
crm left join mc would return all of those, plus all the rows in crm that don't have any match in mc (the mc.* fields would be NULL in these result rows).
-- john r pierce 37N 122W somewhere on the middle of the left coast -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
