Sergio H. Gonzalez wrote:

> select ID,descripcion from STOCK
> union ALL
> select id,razon_social from proveedores
> order by 1
>
> PLAN (STOCK NATURAL)
> PLAN (PROVEEDORES NATURAL)

NATURAL means that no index is used. Do you have index on stock.ID or
preoveedores.ID ?

--
Milan Babuskov
http://www.flamerobin.org
http://www.guacosoft.com