Nope. You'd do at most one transaction, around the transactional part. You wouldn't wrap an external call in a transaction: if it's not transactional, you're li

Nope. You'd do at most one transaction, around the transactional part. You wouldn't wrap an external call in a transaction: if it's not transactional, you're literally doing nothing but adding load to your database. If your DB doesn't have access to the data, the transaction is meaningless: your database can't roll back the state. And if the Update Balances call is a single SQL statement, you actually wouldn't use any transactions at all. You'd just issue the write and have it be written. No point adding the overhead of a transaction if it isn't doing anything.