Thread: BUG #2381: LIMIT 1 very very lazy than without

The following bug has been logged online:

Bug reference:      2381
Logged by:          Peter Krauss
Email address:      krauss@i-node.com.br
PostgreSQL version: 7.4
Operating system:   Linux
Description:        LIMIT 1 very very lazy than without
Details:

The single query (on psql) is fary fast
(less than 1 sec)

 SELECT a,b,c,d FROM products_view WHERE
 sku='0-123-0-0-6024-20'
 OR lower(codfornecedor)=lower('0-123-0-0-6024-20')
 OR lower(eanfor)=lower('0-123-0-0-6024-20')
 OR lower(refprodfornecedor)=lower('0-123-0-0-6024-20');
 -- ~0.1 second

BUT, IF I ADD a "LIMIT 1", it consumes 2 minutes!

 SELECT a,b,c,d FROM products_view WHERE
 sku='0-123-0-0-6024-20'
 OR lower(codfornecedor)=lower('0-123-0-0-6024-20')
 OR lower(eanfor)=lower('0-123-0-0-6024-20')
 OR lower(refprodfornecedor)=lower('0-123-0-0-6024-20')
 LIMIT 1;
-- ~ 2 minutes !!

""Peter Krauss"" <krauss@i-node.com.br> wrote
>
> The single query (on psql) is fary fast
> (less than 1 sec)
>
>  SELECT a,b,c,d FROM products_view WHERE
>  sku='0-123-0-0-6024-20'
>  OR lower(codfornecedor)=lower('0-123-0-0-6024-20')
>  OR lower(eanfor)=lower('0-123-0-0-6024-20')
>  OR lower(refprodfornecedor)=lower('0-123-0-0-6024-20');
>  -- ~0.1 second
>
> BUT, IF I ADD a "LIMIT 1", it consumes 2 minutes!
>
>  SELECT a,b,c,d FROM products_view WHERE
>  sku='0-123-0-0-6024-20'
>  OR lower(codfornecedor)=lower('0-123-0-0-6024-20')
>  OR lower(eanfor)=lower('0-123-0-0-6024-20')
>  OR lower(refprodfornecedor)=lower('0-123-0-0-6024-20')
>  LIMIT 1;
> -- ~ 2 minutes !!
>

Can you post the \d of products_view and EXPLAIN ANALYZE results of these
two queries from psql?

Regards,
Qingqing