When you create a mapping, you must add one or more source definitions to it. When you drag a source into the Mapping Designer workspace, you add an instance of the source definition to the mapping. The Mapping Designer displays source instances in read-only mode. Every mapping requires at least one transformation object that determines how the Informatica Server reads the source data:
- Source Qualifier transformation. Represents data read from relational and flat file sources.
- Normalizer transformation. Represents data read from COBOL sources.
- ERP Source Qualifier transformation. Represents data read from ERP sources.
- XML Source Qualifier transformation. Represents data read from XML sources.
You can let the Designer create the Source Qualifier by default, so each time you drag a source into a mapping, the Designer adds a Source Qualifier and connects it to the source. Use the automatic Source Qualifier creation when you want to create one Source Qualifier or Normalizer for each source in your mapping. You can disable the automatic creation when you want to join data from different relational sources. You can then manually create and connect it to the source. When you edit the source in the Source Analyzer, all instances of the source in mappings inherit the changes. Some changes might invalidate the mappings using the source. When you add a source definition with the slash character (/) in the table name to mapping, the Designer replaces the slash character with an underscore character in the source instance name for the mapping.