Restore referencial integrity

Hi,

We had by mistake dropped the referencial integrety between two huge tables
and now I'm facing the following messages when trying to recreate the
foreign key again:

alter table posicoes_controles add
CONSTRAINT protocolo FOREIGN KEY (protocolo)
REFERENCES posicoes (protocolo) MATCH SIMPLE
ON UPDATE NO ACTION ON DELETE CASCADE;

ERROR: insert or update on table "posicoes_controles" violates foreign key
constraint "protocolo"
DETAIL: Key (protocolo)=(338525035) is not present in table "posicoes".
********** Erro **********
ERROR: insert or update on table "posicoes_controles" violates foreign key
constraint "protocolo"
SQL state: 23503
Detalhe: Key (protocolo)=(338525035) is not present in table "posicoes".
As the error message tells, the table "posicoes_controles" has values in
column "protocolo" that are not present in column "protocolo" of table
"posicoes". This happened because some programs removed rows from table
"posicoes" while the referencial integrity was dropped.

Now I need to remove all rows from table "posicoes_controles" that has not
corresponding row in table "posicoes".

As these are huge tables, almost 100GB each, and the server
hardware restricted (4GB RAM) I would like a suggestion of which command
or commands should be used from the performance perspective.

Column "protocolo" is "posicoes" table primary key but is not in any index
colum of table "posicoes_controles".

Thank you very much for any help!

--
Reimer
47-3347-1724 47-9183-0547 msn: carlos(dot)reimer(at)opendb(dot)com(dot)br