In Oracle, the old value of a table is stored in "old". This is used
in Karl Goldstein's data model in some triggers he's written. An
example:
create or replace trigger ad_content_revisions_tr
begin update on ad_content_local
for each row
begin
insert into ad_content_revisions (
content_id,...
) values (
:old.content_id,...
);
end;
The colon before old.content_id is a preprocessor that Oracle uses to
look up the value of old. Old is stored from a previous buffer.
The question is, does anyone know of a similar construct I can apply
to PostgreSQL? If I understand the whole system correctly, we're
enforing audit table integrity with this trigger. So, the tradeoff
would be that we'd have no real audit capabilities without thinking of
something that works in PostgreSQL.
