The Data Integration Service applies optimization methods to reduce the number of rows to process in the mapping. You can configure the optimizer level for the mapping to limit which optimization methods the Data Integration Service applies.
The Data Integration Service can apply the following optimization methods:
Pushdown optimization
Early projection optimization
Early selection optimization
Branch pruning optimization
Push-into optimization
Predicate optimization
Global predicate optimization
Cost-based optimization
Dataship-join optimization
Semi-join optimization
The Data Integration Service can apply multiple optimization methods to a mapping at the same time. For example, the Data Integration Service applies the early projection optimization, predicate optimization, global predicate optimization, branch pruning optimization, and early selection optimization or push-into optimization methods when you select the normal optimizer level.