Audit trail

Hi all,

I am wondering if anyone has any good solutions for having postgres
leave an audit trail. Specifically I would like it to copy rows to a
ghost table without constraints every time a row is modified, deleted
etc. I don't really want to have to do the work of creating said ghost
tables, but if that's the only way, then that's ok.

I know about Audit Trail, and it seems ok, but it's not suitable here
because:

1. It doesn't copy whole rows
2. It requires that your tables adhere to a particular structure (I'm
new in this company and I'm slowly migrating tables to a structure that
is close enough that it could be made to work, but for now I'm stuck
with what's here)

Is it best to write some triggers or has someone already done this
stuff?

Thanks,

James.