Transaction progress

Hi,
is there any way to know a transaction progress state ? I'm executing queries from psql and I have a query running for
24hours, 
and I don't know when It will end, is there any way I could know it ?
if not, can I estimate the time from the explain result ? how ?
this is the explain result about the query I'm running:

Hash Join  (cost=100347487.59..145240934.03 rows=26 width=60)
  ->  Index Scan using inars_rectificaciones_inx on inars_rectificaciones b2  (cost=0.00..37839140.62 rows=9546466
width=34)
  ->  Hash  (cost=100347379.07..100347379.07 rows=43407 width=26)
        ->  Seq Scan on inars_nocontrib_perm1  (cost=100000000.00..100347379.07 rows=43407 width=26)

and this is the query:

update inars_nocontrib_perm1  set
rectificada=TRUE,actividad=b2.actividad,presentacion=b2.presentacion,remuneracion=b2.remuneracionfrom
inars_rectificacionesb2 where inars_nocontrib_perm1.cuil=b2.cuil and inars_nocontrib_perm1.cuit=b2.cuit and
inars_nocontrib_perm1.ano=b2.anoand inars_nocontrib_perm1.mes=b2.mes; 

Thank's in advance,

Pablo Yaggi