Pretty bad subject description... but let me try to explain.I'm trying to figure out what would be the most efficient way to query data from multiple tables using a foreign key.
SELECT [...]
FROM (SELECT reference_id, [...] FROM table_where_referenced_id_is_a_pk WHERE reference_id EXISTS/IN/JOIN)
src
LEFT JOIN type1 USING (reference_id)
LEFT JOIN type2 USING (reference_id)
[...]
Or consider whether PostgreSQL Inheritance would work - though basically its a friendly API over the "UNION ALL" query you proposed.
David J.
