Transformations > Source transformation > Reading hierarchical data in an elastic mapping
  

Reading hierarchical data in an elastic mapping

You can use a Source transformation in an elastic mapping to read hierarchical data from complex files, such as Avro, JSON, and Parquet files. The elastic mapping represents the data as an array, map, or struct.
You can use the hierarchical fields as pass-through fields to convert data from one complex file format to another. For example, you can read hierarchical data from an Avro source and write the data to a JSON target. You can also use the hierarchical fields and their child fields in expressions and conditions in downstream transformations. For information about accessing child fields, see the Function Reference.
You can pass hierarchical fields to the following transformations:

Rules and guidelines for reading hierarchical data

Consider the following guidelines when you read hierarchical data: