Optionally, you can create a schema for CSV data that lacks a header row to specify field (column) names and field delimiter characters. For more information about schemas, see CSV File Headers and Schemas.
You can also specify non-standard field delimiters by using the ROWFORMAT parameter of the USING clause. However, if a field delimiter is also specified in an associated CSV schema, the schema specification takes precedence.
Make sure CSV values that will be used or cast as numeric values are not enclosed in quotes. If you cast a value enclosed in quotes to a numeric, it returns a null value or a skipped record error.
External CSV files can be compressed in GZIP format. Other forms of file compression are not supported.