You mean this function: https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_...? I don't get that Postgres RDS only allows you to import from csv, while the exports are strictly parquet. I know that Postgres implements the COPY command using csv or binary, but i would expect some end-to-end lifecycle implementation by AWS and parquet would at least enforce some schema and reduce some errors including those which caused yours.