A mapping is a set of source and target definitions linked by transformation objects that define the rules for data transformation. Mappings represent the data flow between sources and targets.

Source and target definitions represent metadata for sources and targets. When you create a source definition, its structure differs depending on the type of source it represents. The source qualifier for a source definition also differs in structure depending on type of source definition.

After you create a source or target definition, you can include it in a mapping to extract data from the source or load data to the target. You can extract source data in batch, change, or real-time mode.

With CDC mappings, it is generally necessary to have multiple mappings: a batch mapping to materialize the target tables from the source tables in preparation for CDC and the CDC mapping itself which then uses extraction map sources for the source tables. To minimize the effort in creating these mappings, create any business rules applicable to both the batch and CDC sessions in mapplets.