PosgreSQL Query Optimization and the Postmaster Process'

DELETE FROM pagelinks USING page WHERE pl_from NOT IN (page_id);

Nested Loop  (cost=494640.60..112115531252189.59 rows=3953377028232000 width=6)
  Join Filter: ("outer".pl_from <> "inner".page_id)"
  ->  Seq Scan on pagelinks  (cost=0.00..5889791.00 rows=293392800 width=17)
  ->  Materialize  (cost=494640.60..708341.51 rows=13474691 width=11)
        ->  Seq Scan on page  (cost=0.00..402211.91 rows=13474691 width=11)

CREATE TABLE temp_to_delete AS(
    (SELECT DISTINCT pl_from FROM pagelinks)
    	EXCEPT
    (SELECT page_id FROM page));
DELETE FROM pagelinks USING temp_to_delete
    WHERE pagelinks.pl_from IN (temp_to_delete.pl_from);

Query returned successfully: 31340904 rows affected, 4415166 ms execution time.