DEA-C01 Practice Test 5

An AWS Glue crawler has typed the order_total field of a JSON dataset as choice<double,string>, because a minority of upstream files emit the value quoted ("19.99") while the rest emit it unquoted. The Glue job that writes the curated Parquet table now fails, and the downstream Athena table must end up with exactly one order_total column of type double, with the quoted values converted.

Which transformation should the data engineer apply to the DynamicFrame?