Explain incremental aggregation?

When using incremental aggregation you apply captured changes in the source to aggregate calculations in a session.If the source changes only incrementally and you can capture changes you can configure the session to process only those changes. This allows the power center server to update your target incrementally rather than forcing it to process the entire source and recalculate the same data each time you run the session.

You can capture new source data.use incremental aggregation when you can capture new source data much time you run the session.Use a stored procedure on filter transformation only new data.

Incremental changes do not significantly change the target.Use incremental aggregation when the changes do not significantly change the target.If processing the incrementally changed source alters more than half the existing target, the session may not benefit from using incremental aggregation. In this case drop the table and recreate the target with complete source data.