I just commented that.
The problem I had was "Parameter sniffing"
A search in Google solved it.
Thanks anyway :)
>I don't see where local variables @dfecha_prom_i and @dfecha_prom_f came from.
>Also it's not a good idea to use meaningless one letter table aliases. They make queries unreadable and hard to maintain.
>
>>I have the most strange situation.
>>I have this code in a Stored procedure:
>>
>>

>>CREATE PROCEDURE crea_ventas_cliente
>>@cid_plan char(10),
>>@error_msg char(100) output
>>
>>AS
>>
>>/*declares here  */
>>insert into monithor..ventas_cliente( cid_plan, cid_clie, carticulos_id, ccategoria_3, cproveedor_id, nimporte, npeso)
>>	select @cid_plan, a.cid_clie, b.carticulos_id, c.ccategoria_3, c.cproveedor_id,
>>	sum(round(b.nimporte_total,2) * (1 - b.lgratuito) * case when a.ctipo_documento_id = 'NC' then -1 else 1 end )
>>	as nimporte,
>>	sum(b.npeso_detalle * case when a.ctipo_documento_id = 'NC' then -1 else 1 end )
>>	as npeso
>>	from
>>	ventas.._movimiento_ventas a,
>>	ventas.._movimiento_ventas_detalle b,
>>	bdmain.._articulos c
>>	where
>>	a.dfecha_documento >= @dfecha_prom_i  and
>>	a.dfecha_documento <= @dfecha_prom_f  and
>>	a.cnumero_documento  = b.cnumero_documento  and
>>	b.carticulos_id       = c.carticulos_id     and
>>	a.ctipo_documento_id = b.ctipo_documento_id and
>>	a.cserie_documento   = b.cserie_documento   and
>>	a.cestado_documento_id <> 'X' and
>>	a.ctipo_documento_id in ('FA', 'BO', 'NC', 'ND') and
>>	b.ckits              <> '1'
>>	group by
>>	a.cid_clie, b.carticulos_id,
>>	c.ccategoria_3, c.cproveedor_id
>>

>>If I call this stored procedure:
>>

>>declare @error2 char(100)
>>exec monithor..crea_ventas_cliente '0000000012',@error2
>>

>>
>>it takes hours to run (at least 5 hours. I stopped execution)
>>
>>
>>But if I run the code directly in the query analyser it only takes 53 seconds to run the insert command. I traced the stored procedure and the delay is in the insert command, but this very same command run directly executes very quick.
>>I already trieb both approach after booting the computer and made sure that the SP code is exactly the same as the direct code.