WOW!
I am in owe. Thanks a lot. Maybe I can send you my project

Anyway, I've got few comments (if you have time):

1. I've learned many things from your code.

2. What I've noticed is that you (and I assume on purpose) repeat yourself,
so for the update trigger you say:
a) if no inserted row then exit
[if 0 = (select count(*) from inserted) then return end if;]
b) then you say:Are there any rows that have not already been
processed by the trigger
[if 0 = (select count(*) from inserted where not exists (select
1 from FooFum_sync_state where FooFum_sync_state.ThePk=
inserted.ThePk) )then return end if;]
But you already verified in a) that the inserted row exists,
so why not do just this:
if ((select count(*) from FooFum_sync_state
where FooFum_sync_state.ThePk=inserted.ThePk) > 0) then return
end if;
to verify that that there are now rows in state table?
c) then again in the insert you verify everything again
[insert into FooFum_sync_state (TriggerTs, ThePk) select @TriggerTs,
ThePk from inserted where not exists (select 1 from
FooFum_sync_state where FooFum_sync_state.ThePk= inserted.ThePk );]
Where I would do insert into FooFum_sync_state (TriggerTs, ThePk)
VALUES (@TriggerTs, inserted.ThePk)
d) even in update you do it with the FROM clause
Are you just extra hugely safe? I've got to re-write a lot of sql
queries to keep up with your standard!

3. The GLOBAL TEMPORARY TABLE is a good idea. I added a boolean column
to both FUM and FOO. In trigger I check if there is a true(or any)
value for that colum.
- If yes it means it is called from trigger, so I do not do an update.
- If no, then it is called from application so an update with a true (or
any) value for the boolean column.


Thanks a lot once more,

Damjan