PostgreSQL v 11
Well this is exciting for me and is going to save tons of work.

You can run transaction of a paradox form using remote server data,
start a transaction, and rollback or commit after any changes.

Process:
1. Use form with all the tables that you want involved in the
transaction using the same alias.
2. Open and run the form. --- IMPORTANT form must be running
3. Start a transaction on that the alias
4. Make as many edits and changes as you want.
5. Commit or rollback the transaction.
Note any changes anywhere you have made using this alias will be rolled
back, whether on this form or not.

So, I go a step further and create a new unique alias, copy the form to
priv directory and change existing alias to my new one.  When doing this
as long as the new alias is the same length as the old it will not
corrupt the form.

Now start you transaction and only data on the new form using the new
alias will be part of the transaction.
This includes any TCURSORS you have opened using the alias as well!
NB: to make sure you open on the correct alias do:
mytc.open( dmgetproperty("PNDM","FULLNAME") )
This has the advantage of causing pdox to refresh  any data immediately
on the form.

-- 
Mark Bannister