On 2/11/08, Tom Lane <[EMAIL PROTECTED]> wrote: > > Chris Kratz <[EMAIL PROTECTED]> writes: > > -> Nested Loop (cost=42.74..161.76 rows=1 width=38) (actual > > time=2.932..27.772 rows=20153 loops=1) > > -> Hash Join (cost=10.89..22.58 rows=1 width=24) (actual > > time=0.065..0.134 rows=1 loops=1) > > Hash Cond: (mtchsrcprj3.funding_source_id = > > mtchsrcprjfs3.nameid) > > -> Seq Scan on project mtchsrcprj3 (cost=0.00..11.22 > > rows=122 width=8) (actual time=0.002..0.054 rows=122 loops=1) > > -> Hash (cost=10.83..10.83 rows=5 width=24) (actual > > time=0.017..0.017 rows=1 loops=1) > > -> Index Scan using name_float_lfm_idx on > > namemaster mtchsrcprjfs3 (cost=0.00..10.83 rows=5 width=24) (actual > > time=0.012..0.013 rows=1 loops=1) > > Index Cond: (name_float_lfm = 'DWS'::text) > > -> Bitmap Heap Scan on transaction_details idatrndtl > > (cost=31.85..121.60 rows=1407 width=22) (actual time=2.864..12.060 > > rows=20153 loops=1) > > Recheck Cond: (idatrndtl.ida_trans_match_source_id = > > mtchsrcprj3.id) > > -> Bitmap Index Scan on > > transaction_details_ida_trans_match_source_id (cost=0.00..31.50 > > rows=1407 width=0) (actual time=2.696..2.696 rows=20153 loops=1) > > Index Cond: (idatrndtl.ida_trans_match_source_id = > > mtchsrcprj3.id) > > > The first frustration is that I can't get the transaction details scan > > to get any more accurate. It thinks it will find 1407 records, > > instead it finds 20,153. Then for whatever reason it thinks that a > > join between 1 record and 1407 records will return 1 record. This is > > mainly what I can't understand. Why does it think it will only get > > one record in response when it's a left join? > > I don't see any left join there ... > > > PG 8.2.4 on Linux kernel 2.6.9 x64 > > The first thing you should do is update to 8.2.6; we've fixed a fair > number of problems since then that were fallout from the outer-join > planning rewrite in 8.2. > > If it still doesn't work very well, please post the pg_stats rows for > the join columns involved (idatrndtl.ida_trans_match_source_id and > mtchsrcprj3.id). (You do have up-to-date ANALYZE stats for both > of those tables, right?) > > regards, tom lane >
Thanks Tom, we will try the upgrade and see if that makes a difference. -Chris
