Re: [HACKERS] Re: [BUGS] General Bug Report: Bug in optimizer

On Thu, 18 Mar 1999, Bruce Momjian wrote:

> > Bruce Momjian wrote:
> > >
> > > Let me tell you why I don't think this is a bug. The optimizer will
> > > choose ordered results over unordered results if the costs are the same.
> > > In this case, the cost of the query is zero, so it chose to use the
> > > index because the index produces an ordered result.
> > >
> > > This works well for un-vacuumed tables, because it thinks everything is
> > > zero cost, and chooses the index.
> >
> > Agreed, this is ok as long as
> >
> > vac=> create table table1 (field1 int);
> > CREATE
> > vac=> insert into table1 values (1);
> > INSERT 1583349 1
> > vac=> create index i_table1__field1 on table1 (field1);
> > CREATE
> > vac=> explain select * from table1 where field1 = 1;
> > NOTICE: QUERY PLAN:
> >
> > Seq Scan on table1 (cost=1.03 size=1 width=4)
> >
> > - SeqScan is used for small tables.
> >
> > So, only bug reported is left.
> >
>
> Can you get on IRC now? Why are you up so late?

That's something we need on our globe...timezones :)

Marc G. Fournier ICQ#7615664 IRC Nick: Scrappy
Systems Administrator @ hub.org
primary: scrappy(at)hub(dot)org secondary: scrappy(at){freebsd|postgresql}.org