Each record read from an input data file must be unique to avoid duplication. key defines a simple unique key for this element comprised of a single field and associated property key name.

Set the key in a mapping script to name:

If the data file includes unique ids, such as a GraphSON or Gryo file written from DataStax Enterprise, the key can be set to identify the id:

where ~id defines that the id is found in the data file, and id renames the field to id in the loaded file.

Set a key in a mapping script to a composite custom id:

This definition uses the following pattern:

where <csv_column_name> is the column in the input file that specifies the value to be assigned to the vertex_property_key in the graph.