Re: Incorrect row estimates in plan?

pgdba <postgresql@inbox.com> writes:
>             ->  Bitmap Heap Scan on slog  (cost=82.98..6434.62 rows=2870
> width=61) (actual time=50.235..1237.948 rows=83538 loops=1)
>                     Recheck Cond: ((gid = 10000) AND (rule = ANY
> ('{1,2,8,9,10}'::integer[])) AND (CASE WHEN (rule = ANY
> ('{8,9}'::integer[])) THEN destip ELSE srcip END = '192.168.10.23'::inet))
>                     ->  Bitmap Index Scan on slog_gri_idx  (cost=0.00..82.26
> rows=2870 width=0) (actual time=41.306..41.306 rows=83538 loops=1)
>                         Index Cond: ((gid = 10000) AND (rule = ANY
> ('{1,2,8,9,10}'::integer[])) AND (CASE WHEN (rule = ANY
> ('{8,9}'::integer[])) THEN destip ELSE srcip END = '192.168.10.23'::inet))

[ blink... ]  Pray tell, what is the definition of this index?

With such a bizarre scan condition, it's unlikely you'll get any really
accurate row estimate.

            regards, tom lane