The Joiner transformation can join data from two related heterogeneous sources. For example, you can use the Joiner transformation to join account information from flat files with data from the Salesforce Account object.
The Joiner transformation joins data based on the join conditions and the join type. A join condition matches fields between the two sources. You can create multiple join conditions. A join type defines the set of data that is included in the results.
When you link a transformation to the Joiner transformation, you connect it to the Master or Detail group. To improve job performance, connect the transformation that represents the smaller data set to the Master group.
To join more than two sources in a mapping, you can use multiple Joiner transformations. You can join the output from the Joiner transformation with another source pipeline. You can add Joiner transformations to the mapping until you join all source pipelines.
Field name conflicts can occur when you join sources with matching field names. You can resolve the conflict in one of the following ways:
Create a field name conflict resolution.
Rename matching fields in an upstream transformation.
Pass data through an Expression transformation to rename fields.