If not already done, create the authorization object. See Example: Create an Authorization Object.
Run the READ_NOS command:
SELECT * FROM ( LOCATION='/s3/td-usgs-public.s3.amazonaws.com/CSVDATA/' AUTHORIZATION=MyAuthObj RETURNTYPE='NOSREAD_SCHEMA' ) AS d;
Your result will be similar to the following:
ColPosition 1
Name GageHeight2
Datatype decimal(3,2)
FileType csv
Location /S3/s3.amazonaws.com/td-usgs-public/CSVDATA/09513780/2018/06/27.csv
ColPosition 2
Name Flow
Datatype decimal(3,2)
FileType csv
Location /S3/s3.amazonaws.com/td-usgs-public/CSVDATA/09513780/2018/06/27.csv
ColPosition 3
Name site_no
Datatype int
FileType csv
Location /S3/s3.amazonaws.com/td-usgs-public/CSVDATA/09513780/2018/06/27.csv
The output is displayed vertically for readability.