>
> I need transaction 4 to know that pkey=3 is the last record that can be
> cronologically copied to my destination database.
> I know transaction 4 can see pkey=5 and pkey=6, but it shouldn't copy
> those records until previous records (in this example pkey=3) are
> commited.
> The replication process is started periodically. So hopefully, next
> time it starts, transaction #3 will already be commited and records
> 4,5,6 will be copied.
>
>

It won't see pk3 if pk 3 records are not committed.
I think you're missing the point. Whatever state the the comitted DB is in,
it's in a consistent state. Whenever your replication process starts it sees
commited records (including your audit table). Your replication process can
safely process those records there and then.
Why don't you download the source of fbreplicator at www.meta.com.au, you
will see quite clearly, the logic behind replication.
Alan