Just FYI: starting with 9.4, PostgreSQL supports the FILTER clause. This would change this: > array_remove(array_agg(producer.last_name), NULL) AS last_names

Just FYI: starting with 9.4, PostgreSQL supports the FILTER clause. This would change this: > array_remove(array_agg(producer.last_name), NULL) AS last_names to that > array_agg(producer.last_name) FILTER(WHERE producer.last_name IS NOT NULL) AS last_names I wrote about FILTER here: http://modern-sql.com/feature/filter http://modern-sql.com/feature/filter And how to use ARRAYs rather than concatenated strings here: http://modern-sql.com/feature/listagg#alternative-array http://modern-sql.com/feature/listagg#alternative-array