-----Original Message----- From: Jeff Amiel [mailto:becauseimjeff@xxxxxxxxx] Sent: Friday, December 02, 2011 3:52 PM To: pgsql-general@xxxxxxxxxxxxxx; David Johnston Subject: RE: Oddball data distribution giving me planner headaches --- On Fri, 12/2/11, David Johnston <polobo@xxxxxxxxx> wrote: > From: David Johnston <polobo@xxxxxxxxx> What kind of plan does the > following give? > > EXPLAIN ANALYZE > SELECT * > FROM customer_rel p > JOIN customer c ON (p.parent_customer = c.customer_id) WHERE > c.customer_type = 'DISTRIBUTOR' Nearly identical output "Nested Loop (cost=0.00..29624.69 rows=931 width=97) (actual time=0.032..1330.208 rows=1025401 loops=1)" " -> Seq Scan on customer c (cost=0.00..25429.10 rows=136 width=71) (actual time=0.017..212.059 rows=68 loops=1)" " Filter: (customer_type = 'DISTRIBUTOR'::bpchar)" " -> Index Scan using rel_parent on customer_rel p (cost=0.00..30.76 rows=7 width=26) (actual time=0.006..7.732 rows=15079 loops=68)" " Index Cond: (parent_customer = c.customer_id)" "Total runtime: 1544.281 ms" ----------------------------------------------------- What happens if you disable, say, nested loops and/or index scans? David J. -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
