Google BigQuery Connectors > Part II: Data Integration with Google BigQuery V2 Connector > Mappings and mapping tasks with Google BigQuery V2 Connector > Hierarchy Builder transformation in mappings
  

Hierarchy Builder transformation in mappings

When you read data from relational sources and write data to a Google BigQuery target, you must use a Hierarchy Builder transformation.
The transformation processes relational input from the upstream transformation and provides JSON output to the downstream transformation. The Hierarchy Builder transformation produces JSON output based on the sample schema of the Google BigQuery table that you associate with the transformation and the way that you map the data.
For more information on using the Hierarchy Builder transformation with Google BigQuery V2 Connector, see the Informatica How-To Library article, "Using a Hierarchical Builder Transformation with Google BigQuery Connector": https://kb.informatica.com/h2l/HowTo%20Library/1/1076-UsingaHierarchicalBuilderTransformationwithGoogleBigQueryConnector-H2L.pdf