Re: Optimizer Selecting Incorrect Index

On Wed, 25 Aug 2004, Richard Huxton wrote:

> >  Index Scan using trptserc on trans  (cost=0.00..465.10 rows=44 width=118)
> >    Index Cond: (trn_patno = 199999)
> >    Filter: ((trn_old_date >= '1994-08-23'::date) AND (trn_old_date <=
> > '2004-08-23'::date) AND (trn_bill_inc = 'B'::bpchar))
> > (687 rows)
>
> >  Index Scan using todate on trans  (cost=0.00..105165.74 rows=1 width=143)
> >    Index Cond: ((trn_old_date >= '1994-08-23'::date) AND (trn_old_date <=
> > '2004-08-23'::date))
> >    Filter: ((trn_patno = 199999) AND (trn_bill_inc = 'B'::bpchar))
> > (713 rows)
>
> These queries are different. The first returns 687 rows and the second
> 713 rows.

The 687 and 713 are the number of rows in the plan, not the number of rows
the queries return.

--
/Dennis Björklund