Run VACUUM ANALYZE and see if the cost estimates became close to the effective rows. This could make it faster.
2007/3/23, Noah M. Daniels <[EMAIL PROTECTED]>:
SLOW: Merge Right Join (cost=1138.78..460482.84 rows=2993 width=405) (actual time=1244745.427..1245714.571 rows=39 loops=1) Merge Cond: ("outer".supplier_alias_id = "inner".id) -> Index Scan using index_customs_records_on_supplier_alias_id on customs_records cr (cost=0.00..6717806.37 rows=1704859 width=363) (actual time=54.567..1245210.707 rows=117424 loops=1) -> Sort (cost=1138.78..1139.53 rows=300 width=46) (actual time=24.093..24.161 rows=39 loops=1) Sort Key: a.id -> Index Scan using index_aliases_company_type_company_id on aliases a (cost=0.00..1126.44 rows=300 width=46) (actual time=22.400..23.959 rows=10 loops=1) Index Cond: ((company_type)::text = 'Supplier'::text) Filter: (company_id IS NULL) Total runtime: 1245714.752 ms FAST: Nested Loop Left Join (cost=0.00..603052.46 rows=3244 width=405) (actual time=68.526..3115.407 rows=1355 loops=1) -> Index Scan using index_aliases_company_type_company_id on aliases a (cost=0.00..639.56 rows=165 width=46) (actual time=32.419..132.286 rows=388 loops=1) Index Cond: ((company_type)::text = 'Buyer'::text) Filter: (company_id IS NULL) -> Index Scan using index_customs_records_on_buyer_alias_id on customs_records cr (cost=0.00..3639.55 rows=915 width=363) (actual time=2.133..7.649 rows=3 loops=388) Index Cond: (cr.buyer_alias_id = "outer".id) Total runtime: 3117.713 ms (7 rows)
-- Daniel Cristian Cruz Analista de Sistemas