Re: Highly obscure and erratic

On Wed, 19 Jun 2002, Varun Kacholia wrote:

>
> > What does explain show for the exists version?
>
> suryadb=# explain select * from dbmedia where EXISTS (select ID from
> wdmedia where word='whatever' AND dbmedia.id=id ) LIMIT 200;
> NOTICE: QUERY PLAN:
>
> Limit (cost=0.00..1006732.42 rows=200 width=76)
> -> Seq Scan on dbmedia (cost=0.00..507810931.25 rows=100883 width=76)
> SubPlan
> -> Index Scan using wdkmedia on wdmedia
> (cost=0.00..5033.63 rows=1 width=4)
>
> EXPLAIN
>
> still seq scan :((

Yeah...

Do either of these run better?

select dbmedia.* from dbmedia, wdmedia where wdmedia.word='whatever' and
dbmedia.id=wdmedia.id;

select * from dbmedia, (select ID from wdmedia where word='whatever') AS w
where w.id=dbmedia.id;

> someone please fix this bug :(
I'd guess it's not that simple.