Data mapping describes how elements are mapped between two distinct data models. To support SQL access to a REST service, the REST endpoint must be mapped to a relational schema. The driver automatically generates a relational view of your data when the Model file is loaded and/or any of the initial sampling of the data in the REST responses has been completed. When generating the relational view, the driver decompounds JSON, CSV, and XML documents returned by endpoints into parent-child tables. The following sections describe how the driver handles mapping of responses for their respective format.

Note:
  • You can use the Qualify Normalized Names option to configure whether the names of relational tables normalized from array columns are derived directly from the column name or prefixed with parent object names. See the "Qualify Normalized Names" connection option description for details.
  • After connecting, you can view the relational mapping of your model through the ER Diagram tab provided in the Autonomous REST Composer. See "Generating a Model file with the Autonomous REST Composer" for more information on using the Autonomous REST Composer.

The driver detects whether a response is in the CSV, JSON, or XML format. If a service supports multiple formats, the driver attempts to use JSON by default. JSON is a more compact format that typically performs better; however, there are some advantages to using the other formats. If you prefer to use a particular format in this scenario, you can specify it in the Accept header by using the #headers object in the table definition of the Model file. See "Request with custom HTTP headers" for more information.