PowerCenter lets you define transactions that the Integration Service uses when it processes transformations and when it commits and rolls back data at a target. You can define a transaction based on a varying number of input rows. A transaction is a set of rows bound by commit or rollback rows, the transaction boundaries. Some rows may not be bound by transaction boundaries. This set of rows is an open transaction. You can choose to commit at end of file or to roll back open transactions when you configure the session.
The Integration Service can process input rows for a transformation each row at a time, for all rows in a transaction, or for all source rows together. Processing a transformation for all rows in a transaction lets you include transformations, such as an Aggregator, in a real-time session.
Transaction boundaries originate from transaction control points. A transaction control point is a transformation that defines or redefines the transaction boundary in the following ways:
Generates transaction boundaries.
The transformations that define transaction boundaries differ, depending on the session commit type:
Target-based and user-defined commit.
Transaction generators generate transaction boundaries. A transaction generator is a transformation that generates both commit and rollback rows. The Transaction Control and Custom transformation are transaction generators.
Some active sources generate commits. They do not generate rollback rows. Also, transaction generators generate commit and rollback rows.
Drops incoming transaction boundaries.
When a transformation drops incoming transaction boundaries, and does not generate commits, the Integration Service outputs all rows into an open transaction. All active sources that generate commits and transaction generators drop incoming transaction boundaries.