Re: Forcing seq_scan off for large table joined with tiny table yeilds improved performance - Mailing list pgsql-performance

Mario Splivalo <mario.splivalo@megafon.hr> writes:
>     ->  Bitmap Heap Scan on photo_info_data u  (cost=39134.84..63740.08
> rows=109024 width=50) (actual time=270.464..270.469 rows=3 loops=2)
>           Recheck Cond: ((u.field_name)::text = (t.key)::text)
>           ->  Bitmap Index Scan on photo_info_data_pk
> (cost=0.00..39107.59 rows=109024 width=0) (actual time=270.435..270.435
> rows=3 loops=2)
>                 Index Cond: ((u.field_name)::text = (t.key)::text)

You need to figure out why that rowcount estimate is off by more than
four orders of magnitude :-(

            regards, tom lane