Tom Lane wrote:
The first-order knob for tuning indexscan vs seqscan costing is
random_page_cost. What have you got that set to?
This is currently at the default of 4. All of my other planner cost
constants are at default values as well. Dropping it to 1 drops the
estimated cost by a comparable ratio:
Index Scan using orders_status_btree_idx on orders o
(cost=1.20..3393.20 rows=7026 width=8) (actual time=0.050..0.314
rows=105 loops=1)
Index Cond: (order_statuses_id = $0)
InitPlan
-> Seq Scan on order_statuses (cost=0.00..1.20 rows=1 width=4)
(actual time=0.017..0.025 rows=1 loops=1)
Filter: ((id_name)::text = 'new'::text)
Total runtime: 0.498 ms
But, I'm guessing that random_page_cost = 1 is not a realistic value.
