Progress
Programming
Handbook
Transactions Defined
A transaction is a set of changes to the database, which the system either completes or discards, leaving no modification to the database. The terms physical transaction and commit unit refer to the same concept as the Progress transaction. For example, in the above scenario where you are adding customer records, each customer record you add is a transaction.
Each iteration of the REPEAT block is a transaction. The transaction is undone (or backed out) if:
In either of these cases, Progress undoes all work it performed since the start of the transaction, as shown in Figure 12–1.
Figure 12–1: Transaction Undo Processing
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So far, you have seen how a transaction can be useful in a situation that involves only a single table. Transactions take on additional importance when you make database changes in multiple tables or records.
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